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Automatic Boot Disk redirector?

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  Automatic Boot Disk redirector? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2012-01-16 08:11 -0500
    Re: Automatic Boot Disk redirector? Arno <me@privacy.net> - 2012-01-16 13:40 +0000
      Re: Automatic Boot Disk redirector? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2012-01-16 09:56 -0500
        Re: Automatic Boot Disk redirector? "R. C. White" <rc@grandecom.net> - 2012-01-16 13:20 -0600
          Re: Automatic Boot Disk redirector? "Rod Speed" <rod.speed.aaa@gmail.com> - 2012-01-17 06:27 +1100
          Re: Automatic Boot Disk redirector? Arno <me@privacy.net> - 2012-01-17 01:30 +0000
          Re: Automatic Boot Disk redirector? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2012-01-17 03:44 -0500
            Re: Automatic Boot Disk redirector? Paul <nospam@needed.com> - 2012-01-17 04:20 -0500
            Re: Automatic Boot Disk redirector? "R. C. White" <rc@grandecom.net> - 2012-01-17 11:53 -0600
              Re: Automatic Boot Disk redirector? Paul <nospam@needed.com> - 2012-01-17 15:42 -0500
                Re: Automatic Boot Disk redirector? Arno <me@privacy.net> - 2012-01-17 21:07 +0000
                  Re: Automatic Boot Disk redirector? Paul <nospam@needed.com> - 2012-01-17 19:23 -0500
                Re: Automatic Boot Disk redirector? "R. C. White" <rc@grandecom.net> - 2012-01-17 20:23 -0600
                  Re: Automatic Boot Disk redirector? Arno <me@privacy.net> - 2012-01-18 03:22 +0000
                  Re: Automatic Boot Disk redirector? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2012-01-18 16:05 -0500
              Re: Automatic Boot Disk redirector? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2012-01-18 15:50 -0500
                Re: Automatic Boot Disk redirector? Wolf K <wekirch@sympatico.ca> - 2012-01-18 16:55 -0500
                  Re: Automatic Boot Disk redirector? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2012-01-18 19:30 -0500
            Re: Automatic Boot Disk redirector? "Rod Speed" <rod.speed.aaa@gmail.com> - 2012-01-18 07:04 +1100
        Re: Automatic Boot Disk redirector? "Rod Speed" <rod.speed.aaa@gmail.com> - 2012-01-17 06:24 +1100
        Re: Automatic Boot Disk redirector? Arno <me@privacy.net> - 2012-01-17 01:29 +0000
    Re: Automatic Boot Disk redirector? Paul <nospam@needed.com> - 2012-01-16 12:58 -0500
      Re: Automatic Boot Disk redirector? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2012-01-17 03:48 -0500

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#2392 — Automatic Boot Disk redirector?

Whenever an external drive is plugged into my PC, the BIOS gets all 
confused and it rearranges the boot order of the drives. You then have 
to go into the BIOS setup and rearrange them back, which is a temporary 
solution until you don't connect external drive and you have to do it 
all over again. Or use the BIOS's boot device chooser which is even more 
temporary.

What I'd like to know is if there is some kind of automatic boot sector 
manager that can be put onto non-boot disks and redirect the boot 
towards the right disk?

	Yousuf Khan

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#2393

In comp.sys.ibm.pc.hardware.storage Yousuf Khan <bbbl67@spammenot.yahoo.com> wrote:
> Whenever an external drive is plugged into my PC, the BIOS gets all 
> confused and it rearranges the boot order of the drives. You then have 
> to go into the BIOS setup and rearrange them back, which is a temporary 
> solution until you don't connect external drive and you have to do it 
> all over again. Or use the BIOS's boot device chooser which is even more 
> temporary.

> What I'd like to know is if there is some kind of automatic boot sector 
> manager that can be put onto non-boot disks and redirect the boot 
> towards the right disk?

>        Yousuf Khan

In theory, a bootable disk has a boot-signature in the
boot-sector, while a non-bootable disk does not have it and
should be skipped. As soon as the boot-secotr is loaded into 
RAM and executed, it is actually too late as the BIOS has
relinquished control to it permenently at this time.

A PC bios expexts 0x55 0xAA in the last two bytes of the 
first sector of a device in order to consider it bootable.
Maybe just overwriting these two bytes with 0x00 0x00 would
do the trick, but maybe it could confuse other software.
It should be easily reversible though in case of problems.

Arno
-- 
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@wagner.name
GnuPG:  ID: 1E25338F  FP: 0C30 5782 9D93 F785 E79C  0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

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#2394

On 1/16/2012 8:40 AM, Arno wrote:
> In theory, a bootable disk has a boot-signature in the
> boot-sector, while a non-bootable disk does not have it and
> should be skipped. As soon as the boot-secotr is loaded into
> RAM and executed, it is actually too late as the BIOS has
> relinquished control to it permenently at this time.
>
> A PC bios expexts 0x55 0xAA in the last two bytes of the
> first sector of a device in order to consider it bootable.
> Maybe just overwriting these two bytes with 0x00 0x00 would
> do the trick, but maybe it could confuse other software.
> It should be easily reversible though in case of problems.
>
> Arno

Does this have anything to do with "active" and "non-active" partitions? 
Because I have already tried removing the active property from any 
partitions that had active set in them. It didn't do anything though.

	Yousuf Khan

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#2396

Hi, Yousuf.

> I have already tried removing the active property from any partitions that 
> had active set in them

This may be a big part of your problem.  In order to boot from a disk, it 
must have exactly ONE "active" partition.  To be marked active ("bootable"), 
that must be a primary partition, not a logical drive in an extended 
partition.

RC
-- 
R. C. White, CPA
San Marcos, TX
rc@grandecom.net
Microsoft Windows MVP (2002-2010)
Windows Live Mail 2011 (Build 15.4.3538.0513) in Win7 Ultimate x64 SP1


"Yousuf Khan"  wrote in message news:4f143abe@news.bnb-lp.com...

On 1/16/2012 8:40 AM, Arno wrote:
> In theory, a bootable disk has a boot-signature in the
> boot-sector, while a non-bootable disk does not have it and
> should be skipped. As soon as the boot-secotr is loaded into
> RAM and executed, it is actually too late as the BIOS has
> relinquished control to it permenently at this time.
>
> A PC bios expexts 0x55 0xAA in the last two bytes of the
> first sector of a device in order to consider it bootable.
> Maybe just overwriting these two bytes with 0x00 0x00 would
> do the trick, but maybe it could confuse other software.
> It should be easily reversible though in case of problems.
>
> Arno

Does this have anything to do with "active" and "non-active" partitions?
Because I have already tried removing the active property from any
partitions that had active set in them. It didn't do anything though.

Yousuf Khan 

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#2398

R. C. White wrote
> Hi, Yousuf wrote
>> Arno wrote

>> I have already tried removing the active property from any partitions that had active set in them

> This may be a big part of your problem.

Unlikely given that changing that made no difference.

> In order to boot from a disk, it must have exactly ONE "active" partition.

Hasnt been like that for a LONG time now.

> To be marked active ("bootable"), that must be a primary partition, not a logical drive in an extended partition.

But there are plenty of boot managers that can boot those too.

>> In theory, a bootable disk has a boot-signature in the
>> boot-sector, while a non-bootable disk does not have it and
>> should be skipped. As soon as the boot-secotr is loaded into
>> RAM and executed, it is actually too late as the BIOS has
>> relinquished control to it permenently at this time.

>> A PC bios expexts 0x55 0xAA in the last two bytes of the
>> first sector of a device in order to consider it bootable.
>> Maybe just overwriting these two bytes with 0x00 0x00 would
>> do the trick, but maybe it could confuse other software.
>> It should be easily reversible though in case of problems.

> Does this have anything to do with "active" and "non-active"
> partitions? Because I have already tried removing the active property
> from any partitions that had active set in them. It didn't do
> anything though.

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#2400

In comp.sys.ibm.pc.hardware.storage R. C. White <rc@grandecom.net> wrote:
> Hi, Yousuf.

>> I have already tried removing the active property from any partitions that 
>> had active set in them

> This may be a big part of your problem.  In order to boot from a disk, it 
> must have exactly ONE "active" partition.  To be marked active ("bootable"), 
> that must be a primary partition, not a logical drive in an extended 
> partition.

No. In order to boot old Windows versions it has to be like that.
But as the BIOS does not undertsnd partitions, it does not understand
whether a partition is active or not.

Arno

-- 
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@wagner.name
GnuPG:  ID: 1E25338F  FP: 0C30 5782 9D93 F785 E79C  0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

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#2404

On 16/01/2012 2:20 PM, R. C. White wrote:
> Hi, Yousuf.
>
>> I have already tried removing the active property from any partitions
>> that had active set in them
>
> This may be a big part of your problem. In order to boot from a disk, it
> must have exactly ONE "active" partition. To be marked active
> ("bootable"), that must be a primary partition, not a logical drive in
> an extended partition.
>
> RC

Well, as I said, I removed all of the partitions previously marked as 
"active", and it made no difference.

It was a royal pain to do it too, because although Windows' Disk 
Management can turn a partition active, but it cannot turn it 
"inactive": what was Microsoft thinking, it costs too much to put the 
reverse command in? Instead, I discovered that you have go to an arcane 
commmand-line based tool called Diskpart to do that. The tool itself is 
not so bad, I figured it out quite quickly, it was just a pain to search 
through Google to find this command in the first place.

	Yousuf Khan

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#2408

Yousuf Khan wrote:
> On 16/01/2012 2:20 PM, R. C. White wrote:
>> Hi, Yousuf.
>>
>>> I have already tried removing the active property from any partitions
>>> that had active set in them
>>
>> This may be a big part of your problem. In order to boot from a disk, it
>> must have exactly ONE "active" partition. To be marked active
>> ("bootable"), that must be a primary partition, not a logical drive in
>> an extended partition.
>>
>> RC
> 
> Well, as I said, I removed all of the partitions previously marked as 
> "active", and it made no difference.
> 
> It was a royal pain to do it too, because although Windows' Disk 
> Management can turn a partition active, but it cannot turn it 
> "inactive": what was Microsoft thinking, it costs too much to put the 
> reverse command in? Instead, I discovered that you have go to an arcane 
> commmand-line based tool called Diskpart to do that. The tool itself is 
> not so bad, I figured it out quite quickly, it was just a pain to search 
> through Google to find this command in the first place.
> 
>     Yousuf Khan

Do you have a copy of PTEDIT32.exe ?

Give that a try and you should be able to see the 0x80 boot flag with that.

ftp://ftp.symantec.com/public/english_us_canada/tools/pq/utilities/PTEDIT32.zip

You can edit the primary partition table, and do things to boot flag if you want.

    Paul

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#2409

Hi, Yousuf.

>  Well, as I said, I removed all of the partitions previously marked as 
> "active", and it made no difference.

Well, as I said, ONE partition on the boot device MUST be "active".  That's 
the partition that will act as the "System Partition" - and that "System" 
label will appear in Disk Management's Status column for that partition.

> Windows' Disk Management can turn a partition active, but it cannot turn 
> it "inactive"

Since there can be only ONE active partition on each disk, you can mark 
Partition 2 inactive by simply making Partition 2 Active.

To make Partition 1 Inactive, right-click on Partition 2 and mark it Active. 
Since Disk Management knows that there can be only one active partition, it 
will automatically remove the Active mark from Partition 1.  If you then 
make Partition 3 Active, both Partitions 1 and 2 will become Inactive.

So, you automatically make Partition 1 INactive by making another primary 
partition Active.

> you have go to an arcane commmand-line based tool called Diskpart to do 
> that.

Yes, the DiskPart shell is very powerful - and arcane - so it must be used 
with care.  Disk Management is really just the "pretty face" GUI for 
DiskPart.  It does MOST of what DiskPart does and in a less-intimidating 
way.  (Earlier Windows had a Diskpart command in the Recovery Console, but 
that was quite limited to just creating and deleting partitions.)

RC
--
R. C. White, CPA
San Marcos, TX
rc@grandecom.net
Microsoft Windows MVP (2002-2010)
Windows Live Mail 2011 (Build 15.4.3538.0513) in Win7 Ultimate x64 SP1


"Yousuf Khan"  wrote in message news:4f1534dd$1@news.bnb-lp.com...

On 16/01/2012 2:20 PM, R. C. White wrote:
> Hi, Yousuf.
>
>> I have already tried removing the active property from any partitions
>> that had active set in them
>
> This may be a big part of your problem. In order to boot from a disk, it
> must have exactly ONE "active" partition. To be marked active
> ("bootable"), that must be a primary partition, not a logical drive in
> an extended partition.
>
> RC

Well, as I said, I removed all of the partitions previously marked as
"active", and it made no difference.

It was a royal pain to do it too, because although Windows' Disk
Management can turn a partition active, but it cannot turn it
"inactive": what was Microsoft thinking, it costs too much to put the
reverse command in? Instead, I discovered that you have go to an arcane
commmand-line based tool called Diskpart to do that. The tool itself is
not so bad, I figured it out quite quickly, it was just a pain to search
through Google to find this command in the first place.

Yousuf Khan 

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#2412

R. C. White wrote:
> Hi, Yousuf.
> 
>>  Well, as I said, I removed all of the partitions previously marked as 
>> "active", and it made no difference.
> 
> Well, as I said, ONE partition on the boot device MUST be "active".  
> That's the partition that will act as the "System Partition" - and that 
> "System" label will appear in Disk Management's Status column for that 
> partition.
> 

This is true in Windows perhaps, but there are other OSes out there.
The boot flag 0x80 is a "suggested serving". The MBR code can look at
it, or ignore it. Windows OSes happen to like it.

I didn't know about this, until one day I had an OS
disk with a Linux distro on it, and no boot flag. Unlike these guys,
I didn't even know there were install options for grub. Grub is a
big mystery to me, and having a grub and grub2 (two streams) doesn't help.

http://www.linuxquestions.org/questions/debian-26/what-is-this-bootable-flag-562885/

    "If you installed grub to MBR, it will boot with or without bootflag"

Virtually every time I install a grub, I get a surprise. For example,
I thought grub stage 1.5 was stored in sectors below 63, and just two
days ago, found a virtually completely clean first 63 sectors, with
no hint of grub at all. Just too many variables, for me to keep track of.

   Paul

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#2413

In comp.sys.ibm.pc.hardware.storage Paul <nospam@needed.com> wrote:
> R. C. White wrote:
>> Hi, Yousuf.
>> 
>>>  Well, as I said, I removed all of the partitions previously marked as 
>>> "active", and it made no difference.
>> 
>> Well, as I said, ONE partition on the boot device MUST be "active".  
>> That's the partition that will act as the "System Partition" - and that 
>> "System" label will appear in Disk Management's Status column for that 
>> partition.
>> 

> This is true in Windows perhaps, but there are other OSes out there.
> The boot flag 0x80 is a "suggested serving". The MBR code can look at
> it, or ignore it. Windows OSes happen to like it.

Actually, Windows is stupid here. Any sane OS loader will be
flexible and just require a partition to be specified to it.
Windows relies on the hostoreic mechanism of the "active" flag.

Despite what some here have said, an arbitrary
number of partitions can be active at the same time. This
is not magic, just one byte in the partirion descriptor
that is 0x80 if active and 0x00 otherwise.

> I didn't know about this, until one day I had an OS
> disk with a Linux distro on it, and no boot flag. Unlike these guys,
> I didn't even know there were install options for grub. Grub is a
> big mystery to me, and having a grub and grub2 (two streams) doesn't help.

Grub-legacy is a finished product. Grub2 is a major redesign and 
under development, but already usable. Chose either as to your needs.

> http://www.linuxquestions.org/questions/debian-26/what-is-this-bootable-flag-562885/

>    "If you installed grub to MBR, it will boot with or without bootflag"

> Virtually every time I install a grub, I get a surprise. For example,
> I thought grub stage 1.5 was stored in sectors below 63, and just two
> days ago, found a virtually completely clean first 63 sectors, with
> no hint of grub at all. 

Stage 1.5 is where you put it, i.e. typically in a file. The 
difference is that stage 1 loads it by knowing its block
numbers on the device, while stage 1.5 does understand filesystems
and loads stage 2 via filesystem addressing. All in the documentation 
here:

http://www.gnu.org/software/grub/manual/legacy/grub.html#Images

> Just too many variables, for me to keep track of.

Then you better not mess with booting. Sorry, not everything is easy.

Arno
-- 
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@wagner.name
GnuPG:  ID: 1E25338F  FP: 0C30 5782 9D93 F785 E79C  0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

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#2414

Arno wrote:

> 
>> Just too many variables, for me to keep track of.
> 
> Then you better not mess with booting. Sorry, not everything is easy.
> 
> Arno

Everything is easy... if it is properly documented.

There was a time, when things *were* properly documented. But that time has passed.

    Paul

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#2415

Hi, Paul.

Yes, I probably should apologize to you and Rod and Arno - and Yousuf.  I'm 
guilty of being focused solely on Windows, especially Win7.  I don't 
normally read comp.sys.ibm.pc.hardware.storage and didn't notice before my 
Replies that Yousuf had cross-posted his question to that NG, as well as to 
alt.windows7.general, where I was reading it.  If I had noticed, I would 
have clarified that my remarks apply only to Windows.  In my youth <g> I 
experimented with other OSes, up until about OS/2, but haven't looked at 
Linux, or at other systems since then.

Thanks for pointing out the differences in booting with non-Windows systems.

RC
--
R. C. White, CPA
San Marcos, TX
rc@grandecom.net
Microsoft Windows MVP (2002-2010)
Windows Live Mail 2011 (Build 15.4.3538.0513) in Win7 Ultimate x64 SP1


"Paul"  wrote in message news:jf4mfi$rqa$1@dont-email.me...

R. C. White wrote:
> Hi, Yousuf.
>
>>  Well, as I said, I removed all of the partitions previously marked as 
>> "active", and it made no difference.
>
> Well, as I said, ONE partition on the boot device MUST be "active". 
> That's the partition that will act as the "System Partition" - and that 
> "System" label will appear in Disk Management's Status column for that 
> partition.
>

This is true in Windows perhaps, but there are other OSes out there.
The boot flag 0x80 is a "suggested serving". The MBR code can look at
it, or ignore it. Windows OSes happen to like it.

I didn't know about this, until one day I had an OS
disk with a Linux distro on it, and no boot flag. Unlike these guys,
I didn't even know there were install options for grub. Grub is a
big mystery to me, and having a grub and grub2 (two streams) doesn't help.

http://www.linuxquestions.org/questions/debian-26/what-is-this-bootable-flag-562885/

    "If you installed grub to MBR, it will boot with or without bootflag"

Virtually every time I install a grub, I get a surprise. For example,
I thought grub stage 1.5 was stored in sectors below 63, and just two
days ago, found a virtually completely clean first 63 sectors, with
no hint of grub at all. Just too many variables, for me to keep track of.

   Paul 

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#2416

Ah, that explains it. No problem.

Arno


In comp.sys.ibm.pc.hardware.storage R. C. White <rc@grandecom.net> wrote:
> Hi, Paul.

> Yes, I probably should apologize to you and Rod and Arno - and Yousuf.  I'm 
> guilty of being focused solely on Windows, especially Win7.  I don't 
> normally read comp.sys.ibm.pc.hardware.storage and didn't notice before my 
> Replies that Yousuf had cross-posted his question to that NG, as well as to 
> alt.windows7.general, where I was reading it.  If I had noticed, I would 
> have clarified that my remarks apply only to Windows.  In my youth <g> I 
> experimented with other OSes, up until about OS/2, but haven't looked at 
> Linux, or at other systems since then.

> Thanks for pointing out the differences in booting with non-Windows systems.

> RC
> --
> R. C. White, CPA
> San Marcos, TX
> rc@grandecom.net
> Microsoft Windows MVP (2002-2010)
> Windows Live Mail 2011 (Build 15.4.3538.0513) in Win7 Ultimate x64 SP1


> "Paul"  wrote in message news:jf4mfi$rqa$1@dont-email.me...

> R. C. White wrote:
>> Hi, Yousuf.
>>
>>>  Well, as I said, I removed all of the partitions previously marked as 
>>> "active", and it made no difference.
>>
>> Well, as I said, ONE partition on the boot device MUST be "active". 
>> That's the partition that will act as the "System Partition" - and that 
>> "System" label will appear in Disk Management's Status column for that 
>> partition.
>>

> This is true in Windows perhaps, but there are other OSes out there.
> The boot flag 0x80 is a "suggested serving". The MBR code can look at
> it, or ignore it. Windows OSes happen to like it.

> I didn't know about this, until one day I had an OS
> disk with a Linux distro on it, and no boot flag. Unlike these guys,
> I didn't even know there were install options for grub. Grub is a
> big mystery to me, and having a grub and grub2 (two streams) doesn't help.

> http://www.linuxquestions.org/questions/debian-26/what-is-this-bootable-flag-562885/

>    "If you installed grub to MBR, it will boot with or without bootflag"

> Virtually every time I install a grub, I get a surprise. For example,
> I thought grub stage 1.5 was stored in sectors below 63, and just two
> days ago, found a virtually completely clean first 63 sectors, with
> no hint of grub at all. Just too many variables, for me to keep track of.

>   Paul 


-- 
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@wagner.name
GnuPG:  ID: 1E25338F  FP: 0C30 5782 9D93 F785 E79C  0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

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#2424

On 17/01/2012 9:23 PM, R. C. White wrote:
> Hi, Paul.
>
> Yes, I probably should apologize to you and Rod and Arno - and Yousuf.
> I'm guilty of being focused solely on Windows, especially Win7. I don't
> normally read comp.sys.ibm.pc.hardware.storage and didn't notice before
> my Replies that Yousuf had cross-posted his question to that NG, as well
> as to alt.windows7.general, where I was reading it. If I had noticed, I
> would have clarified that my remarks apply only to Windows. In my youth
> <g> I experimented with other OSes, up until about OS/2, but haven't
> looked at Linux, or at other systems since then.
>
> Thanks for pointing out the differences in booting with non-Windows
> systems.

Well, maybe I should've asked in a Linux group as well, since it is 
installed and it gets affected as well. But the majority of my debugging 
is being done under Windows, so I didn't want to confuse the issue.

I'm also using Grub (Legacy) as my boot loader on my boot disk, but that 
really doesn't make a difference to this problem. Whether I'm using Grub 
or Windows' own loader directly, they are both effectively bypassed when 
the boot disk order gets messed up by the BIOS.

So getting back to the original problem, there is no boot disk 
redirector utility that can effectively just tell the BIOS that "Hey, 
I'm not the boot disk, go to the next disk"?

	Yousuf Khan

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#2423

On 17/01/2012 12:53 PM, R. C. White wrote:
> Hi, Yousuf.
>
>> Well, as I said, I removed all of the partitions previously marked as
>> "active", and it made no difference.
>
> Well, as I said, ONE partition on the boot device MUST be "active".
> That's the partition that will act as the "System Partition" - and that
> "System" label will appear in Disk Management's Status column for that
> partition.

Well, obviously I left the one disk with an active partition alone, the 
one that I actually intend to boot with.

>> Windows' Disk Management can turn a partition active, but it cannot
>> turn it "inactive"
>
> Since there can be only ONE active partition on each disk, you can mark
> Partition 2 inactive by simply making Partition 2 Active.
>
> To make Partition 1 Inactive, right-click on Partition 2 and mark it
> Active. Since Disk Management knows that there can be only one active
> partition, it will automatically remove the Active mark from Partition
> 1. If you then make Partition 3 Active, both Partitions 1 and 2 will
> become Inactive.
>
> So, you automatically make Partition 1 INactive by making another
> primary partition Active.

I see the problem here, you're not aware that my system has six internal 
hard disks in it, as well as occasionally 3 external ones. When I said I 
had multiple active partitions, I meant they were active over different 
disks, not on the same disk.

This is why I asked the question in the first place, when external disks 
are occasionally plugged in during boot, they mess up the hard disk 
priority order in the BIOS. So a drive that is not my boot disk may be 
listed ahead of my boot disk in the BIOS disk priority.

>> you have go to an arcane commmand-line based tool called Diskpart to
>> do that.
>
> Yes, the DiskPart shell is very powerful - and arcane - so it must be
> used with care. Disk Management is really just the "pretty face" GUI for
> DiskPart. It does MOST of what DiskPart does and in a less-intimidating
> way. (Earlier Windows had a Diskpart command in the Recovery Console,
> but that was quite limited to just creating and deleting partitions.)

Yeah, I can remember using something similar to diskpart in the XP & 
2000 command-line recovery console.

	Yousuf Khan

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#2425

On 18/01/2012 3:50 PM, Yousuf Khan wrote:
>
> This is why I asked the question in the first place, when external disks
> are occasionally plugged in during boot, they mess up the hard disk
> priority order in the BIOS. So a drive that is not my boot disk may be
> listed ahead of my boot disk in the BIOS disk priority.

This is weird. If physical disk zero (HDD-0 on my BIOS) is the first 
boot device, then that's the one it should boot from. Maybe you haven't 
plugged your boot drive into the disk-zero location. Both SATA and IDE 
count the disk number from one end of the plug strip/bank to the other, 
make sure you've connected the disks and the external plugs in the 
correct sequence.

HTH&GoodLuck,
Wolf K.

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#2427

On 18/01/2012 4:55 PM, Wolf K wrote:
> On 18/01/2012 3:50 PM, Yousuf Khan wrote:
>>
>> This is why I asked the question in the first place, when external disks
>> are occasionally plugged in during boot, they mess up the hard disk
>> priority order in the BIOS. So a drive that is not my boot disk may be
>> listed ahead of my boot disk in the BIOS disk priority.
>
> This is weird. If physical disk zero (HDD-0 on my BIOS) is the first
> boot device, then that's the one it should boot from. Maybe you haven't
> plugged your boot drive into the disk-zero location. Both SATA and IDE
> count the disk number from one end of the plug strip/bank to the other,
> make sure you've connected the disks and the external plugs in the
> correct sequence.

No, it's quite definitely disk #0 (first disk enumerated). But for some 
reason my BIOS feels the need to give external disks higher priorities 
whenever they are plugged in, until I manually reorder their priorities 
in the BIOS setup.

	Yousuf Khan

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#2410

Yousuf Khan wrote
> R. C. White wrote

>>> I have already tried removing the active property from any
>>> partitions that had active set in them

>> This may be a big part of your problem. In order to boot from a
>> disk, it must have exactly ONE "active" partition. To be marked
>> active ("bootable"), that must be a primary partition, not a logical
>> drive in an extended partition.

> Well, as I said, I removed all of the partitions previously marked as
> "active", and it made no difference.

> It was a royal pain to do it too, because although Windows' Disk
> Management can turn a partition active, but it cannot turn it
> "inactive": what was Microsoft thinking, it costs too much to put the
> reverse command in?

Nope, they just realise that if only one can be active, it makes more
sense to automatically mark just one active when the user specifys which one to make active.

> Instead, I discovered that you have go to an arcane commmand-line based tool called Diskpart to do that. The tool
> itself is not so bad, I figured it out quite quickly, it was just a pain to search through Google to find this command 
> in the first place.

Hardly the end of civilisation as we know it when modern systems
dont use the active flag for anything at all, as you discovered.

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#2397

Yousuf Khan wrote
> Arno wrote

>> In theory, a bootable disk has a boot-signature in the
>> boot-sector, while a non-bootable disk does not have it and
>> should be skipped. As soon as the boot-secotr is loaded into
>> RAM and executed, it is actually too late as the BIOS has
>> relinquished control to it permenently at this time.

>> A PC bios expexts 0x55 0xAA in the last two bytes of the
>> first sector of a device in order to consider it bootable.
>> Maybe just overwriting these two bytes with 0x00 0x00 would
>> do the trick, but maybe it could confuse other software.
>> It should be easily reversible though in case of problems.

> Does this have anything to do with "active" and "non-active" partitions?

Nope, thats a different issue entirely.

> Because I have already tried removing the active property from any partitions that had active set in them. It didn't 
> do anything though.

Yeah, most bios just ignore that now when deciding what is bootable. 

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