Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

Running Windows XP Pro 64-bit edition. I notice that my primary hard drive
is Disk 0. If I add another hard disk to the system, the primary hard drive
becomes Disk 1! And still works!!! I thought the hard and fast rule was
that disk 0 ALWAYS stays disk 0 REGARDLESS of whether or not an additional
hard drive gets installed. The additional drive in my case is a removable
drive which sits inside a drive bay which replaces the CD-ROM. Am I missing
something?

Well, you are probably right - AND you are probably missing something? If
your original HD (0) is a SATA drive, which would be reasonable to assume,
when you add a drive that is IDE/ATA the BIOS enumerates this one before the
SATA drive. Since SATA is an extensiion of ATA it looks up all IDE
connections first as it used to and any SATA drives are relegated to second
place in this regard. The BIOS is smart enough to keep CD drives separate
and you may somewhere have a setting where you can configure the added HD
separate from the internal one(s), or different connectors to attach your
cables. You should read your Motherboard Manual carefully, if you end up
adding an internal HD later you could have havoc play with your boot order.


Tony. . .




"Spin" <Spin@invalid.com> wrote in message
news:6624ghF2i6bk9U1@mid.individual.net...
> Running Windows XP Pro 64-bit edition. I notice that my primary hard
drive
> is Disk 0. If I add another hard disk to the system, the primary hard
drive
> becomes Disk 1! And still works!!! I thought the hard and fast rule was
> that disk 0 ALWAYS stays disk 0 REGARDLESS of whether or not an additional
> hard drive gets installed. The additional drive in my case is a removable
> drive which sits inside a drive bay which replaces the CD-ROM. Am I
missing
> something?
>
>
>

Spin wrote:

> Running Windows XP Pro 64-bit edition. I notice that my primary hard drive
> is Disk 0. If I add another hard disk to the system, the primary hard drive
> becomes Disk 1! And still works!!! I thought the hard and fast rule was
> that disk 0 ALWAYS stays disk 0 REGARDLESS of whether or not an additional
> hard drive gets installed. The additional drive in my case is a removable
> drive which sits inside a drive bay which replaces the CD-ROM. Am I missing
> something?

NT-based versions of Windows do not rely on the physical detect order of
hard drives by the BIOS in a computer. They rely on a signature placed
in the MBR of each hard drive. Then when you move drives around between
different controllers on the motherboard or to daughercard controller
cards the OS can still locate the appropriate partitions on wherever the
drives got moved. However, moving the drives around can screw up the
BIOS bootup sequence since the BIOS only looks for the bootstrap code in
the MBR on the first physically detected hard disk.

http://en.wikipedia.org/wiki/Master_..._disk_identity

Hard to know what really happened because you did not describe your
physical hardware configuration before and after adding the new hard
disk.

"Tony Sperling" <tony.sperling@dbREMOVEmail.dk> wrote in message
news:eKZ08AcmIHA.1768@TK2MSFTNGP05.phx.gbl...
> Well, you are probably right - AND you are probably missing something? If
> your original HD (0) is a SATA drive, which would be reasonable to assume,
<snipped>

Great answer! The primary drive is SATA and the secondary drive is ATA.
Your explanation rhymes reasonably!

"VanguardLH" <V@nguard.LH> wrote in message
news:SvadnVgpr4dwYmbanZ2dnUVZ_oKhnZ2d@comcast.com. ..
> NT-based versions of Windows do not rely on the physical detect order of
> hard drives by the BIOS in a computer. They rely on a signature placed
> in the MBR of each hard drive. Then when you move drives around between

Thx for your feedback. I will take this knowledge and build upon it.

VanguardLH wrote:

> Spin wrote:
>
>
>>Running Windows XP Pro 64-bit edition. I notice that my primary hard drive
>>is Disk 0. If I add another hard disk to the system, the primary hard drive
>>becomes Disk 1! And still works!!! I thought the hard and fast rule was
>>that disk 0 ALWAYS stays disk 0 REGARDLESS of whether or not an additional
>>hard drive gets installed. The additional drive in my case is a removable
>>drive which sits inside a drive bay which replaces the CD-ROM. Am I missing
>>something?
>
>
> NT-based versions of Windows do not rely on the physical detect order of
> hard drives by the BIOS in a computer. They rely on a signature placed
> in the MBR of each hard drive. Then when you move drives around between
> different controllers on the motherboard or to daughercard controller
> cards the OS can still locate the appropriate partitions on wherever the
> drives got moved. However, moving the drives around can screw up the
> BIOS bootup sequence since the BIOS only looks for the bootstrap code in
> the MBR on the first physically detected hard disk.
>
> http://en.wikipedia.org/wiki/Master_..._disk_identity
>
> Hard to know what really happened because you did not describe your
> physical hardware configuration before and after adding the new hard
> disk.

Actually, there is another layer (underneath the signature mechanism)
that creates the Harddisk# directory, this is done by the Disk Class
driver and the I/O manager when NT is in the early booting stage. These
disk objects such as \device\harddisk0 are created before the I/O
Manager calls the IoAssignDriveLetters function which in turn reads the
registry and assigns drive letters to the NT disk Objects created
earlier by the Disk Class Driver. It is not unconceivable that the disk
ordinal number be different in the Disk Manager and that the
partition(s) on the disk still retain their assigned drive letters.

John

"Spin" <Spin@invalid.com> wrote in message
news:662p7oF2iklcpU1@mid.individual.net...
> Great answer! The primary drive is SATA and the secondary drive is ATA.
> Your explanation rhymes reasonably!

Anyway I can tell the system, to enumerate IDE AFTER SATA (instead of the
default which is IDE first)?

Spin wrote:
> "Spin" <Spin@invalid.com> wrote in message
> news:662p7oF2iklcpU1@mid.individual.net...
>> Great answer! The primary drive is SATA and the secondary drive is ATA.
>> Your explanation rhymes reasonably!
>
> Anyway I can tell the system, to enumerate IDE AFTER SATA (instead of the
> default which is IDE first)?

Unless such an option exists in BIOS (which seems highly unlikely), I doubt
it.

Bill in Co. wrote:
> Spin wrote:
>> "Spin" <Spin@invalid.com> wrote in message
>> news:662p7oF2iklcpU1@mid.individual.net...
>>> Great answer! The primary drive is SATA and the secondary drive is ATA.
>>> Your explanation rhymes reasonably!
>> Anyway I can tell the system, to enumerate IDE AFTER SATA (instead of the
>> default which is IDE first)?
>
> Unless such an option exists in BIOS (which seems highly unlikely), I doubt
> it.

I have seen a BIOS where the boot priority of the hard drives
can be set and this changes the disk numbering too.


Uwe

Like Bill says - any such option will have to sit in the BIOS, but I do not
think it must be 'Highly Unlikely' - I have more than one machine of
different brands running that does this, but it is highly likely that you
should have to be on good friednly terms with your BIOS - you may have an
option to flash to a newer version, or simply do it the hard way and
close-read every single word that appears in every single page inside the
BIOS Setup.

You may have an IDE sub-section under the Advanced section, if you enter
this you can see the devices that the machine is currently aware of, and you
can usually arrange them with the '+' / '-' keys. Your controlling keys may
vary according to the language of the keyboard - whatever you have will fit
the english keyboard but the manufacturer usually made provisions for this
so it boots in a keyboard/language transparant way, you may have to
experiment there. It's usually not a problem.

Do Not Make Changes That You Don't Understand!
-----------------------------------------------------

For a good starting-point, I would go ahead and turn OFF every single
setting in the BIOS that you KNOW that you are not going to need, things
that support devices that are not installed, it's a great exercise and it
will shorten the time it takes the machine to Boot and it may become more
stable or robust.

If you don't have your Motherboard Manual, get it! Most manufacturer's have
it for download in the BIOS and Driver Support section. When You have it,
read it and get familiar with it, your digital buddy will thank you for it!

If it's a Notebook, you may have 'close-to-nothing' that can be changed in
the BIOS, then you are out of luck, but you may have an option to attach
and/or remove devices before installing the OS, it will usually remember the
state it was in when the OS was originally installed! (Vista has changed
this a bit. . .)

Log on to the site that has drivers and BIOS updates for download of your
system - it should have some kind of Forum, register yourself and if it's
any good, get to be a regular and you'll probably have a selection of
knowledgeable people helping you out with any issues that are directed
towards YOUR specific issues.

Good Luck!


Tony. . .






"Bill in Co." <not_really_here@earthlink.net> wrote in message
news:uLQ8bwfmIHA.1164@TK2MSFTNGP02.phx.gbl...
> Spin wrote:
> > "Spin" <Spin@invalid.com> wrote in message
> > news:662p7oF2iklcpU1@mid.individual.net...
> >> Great answer! The primary drive is SATA and the secondary drive is
ATA.
> >> Your explanation rhymes reasonably!
> >
> > Anyway I can tell the system, to enumerate IDE AFTER SATA (instead of
the
> > default which is IDE first)?
>
> Unless such an option exists in BIOS (which seems highly unlikely), I
doubt
> it.
>
>