2 Harddisk with the same drive letters

[flahmeshess]

I have 2 harddisk, 1 installed with Win2K and one with WinXP. Both
have the same drive letters, C,D,E. The OS is installed on C.

I would attached 1 drive at a time to start up the OS. I need to copy
some files across (without using an external HDD). What would happen
if I attached both the drives ? Would the OS be corrupted and then
not be bootable ?

Thanks.

 

[Pegasus \(MVP\)]

I have 2 harddisk, 1 installed with Win2K and one with WinXP. Both
have the same drive letters, C,D,E. The OS is installed on C.

I would attached 1 drive at a time to start up the OS. I need to copy
some files across (without using an external HDD). What would happen
if I attached both the drives ? Would the OS be corrupted and then
not be bootable ?

Thanks.

One disk will be the primary master disk. It will retain the
existing drive letters C:, D: and E:. The other will be a
slave disk or a secondary master disk. It will be assigned
the next available letters. When you reconnect it by itself
later on, it will use the original letters C:, D: and E:.

 

[flahmeshess]

Thanks Pegasus.
That's interesting. That means that I didn't have to unplug the
harddisk in the first place.

What do I need to do in this case ? When I'm in WinXP, before I
reboot, I mark the Win2K partition as active and then reboot ? Then
when I want to reboot WinXP, I mark the Win2K as active ? Is that
what I need to do ?

As I have unplug the Win2K to install my WinXP, now I don't have dual
boot. How do I create dual boot now that both the OS are running ?
In my Win2K, I have a panel that allows me to select to boot to OS or
Recovery console, can I make use of that ? Can point me to any
website that teaches me how to update the file to include WinXP as
another OS to boot ?

Thanks !!!!!!!

 

[Pegasus \(MVP\)]

Thanks Pegasus.
That's interesting. That means that I didn't have to unplug the
harddisk in the first place.

What do I need to do in this case ? When I'm in WinXP, before I
reboot, I mark the Win2K partition as active and then reboot ? Then
when I want to reboot WinXP, I mark the Win2K as active ? Is that
what I need to do ?

As I have unplug the Win2K to install my WinXP, now I don't have dual
boot. How do I create dual boot now that both the OS are running ?
In my Win2K, I have a panel that allows me to select to boot to OS or
Recovery console, can I make use of that ? Can point me to any
website that teaches me how to update the file to include WinXP as
another OS to boot ?

Thanks !!!!!!!

==============================

Multi-booting is a completely different question than the one you
started off with. There are several ways to do it:
- Use the native Windows boot manager, by adjusting c:\boot.ini
to suit your requirements. Very primitive and in your case not
an option.
- Use the BIOS to make one or the other disk the primary master.
Some BIOSs can do it, others can't. I think it's a clumsy method.
- Use a proper boot loader. The good ones let you boot into
any partition and hide other partitions selectively.

The one I use is XOSL (free). In your case I would create a
15 MByte XOSL partition on either disk and take it from there.
However, I would first play with it, using a spare disk, until I
was completely at ease with it. If you have a free IDE slot and
if you can lay your hands on an old hard disk (ask your friendly
computer dealer if he has a very small disk!) then you could use
it for XOSL, completely risk-free.

There are several other boot loaders. Create another post,
asking for further suggestions.

 

[flahmeshess]

Hi ! Wow...thanks very much for the detail explanation. But if I
decided to just plug in 2 harddisk and just use the BIOS to select
which one to boot up, it will work, right ? When I select Win2K
harddisk, all the drive letters on that HDD will be correctly assigned
and the driver letter on the WinXP will be changed by Win2K. When I
use BIOS to select the WinXP, all the drive letters on the WinXP HDD
will be correctly assigned while the drive letter on the Win2K HDD
will be changed by WinXP.... so did I understand your post correctly ?

 

[Pegasus \(MVP\)]

Hi ! Wow...thanks very much for the detail explanation. But if I
decided to just plug in 2 harddisk and just use the BIOS to select
which one to boot up, it will work, right ? When I select Win2K
harddisk, all the drive letters on that HDD will be correctly assigned
and the driver letter on the WinXP will be changed by Win2K. When I
use BIOS to select the WinXP, all the drive letters on the WinXP HDD
will be correctly assigned while the drive letter on the Win2K HDD
will be changed by WinXP.... so did I understand your post correctly ?

=================

I have never used the BIOS method myself - I only read about it
in reports from other posters. You would have to try it for yourself
or create another thread to get more details. Whatever you do, you
must ensure that the current drive letters remain as they are. Since
both installations use C: as the system drive, they must retain C:. If
you attempt to launch Windows off D:, for example, then you will
either have a system that uses some files on D: and others on C:
(which is bad) or you won't be able to log on (which is worse).
Having a second PC that is networked to the test PC would essential
for the subsequent repair/recovery process.

Create another post and ask about multi-booting!

 

[flahmeshess]

Ok. Thanks for your help. I'll think about using the SOXL or stick
to my plug unplug method. Once my migration to WinXP is complete, I
won't need my Win2K.

 

[John John (MVP)]

You can toggle the drives in the BIOS (without unplugging them) and the
installations will maintain their respective drive letter assignment
when they are booted, the Mount Manager's drive letter assignment is
persistent and it will be respected.

You can also boot the Windows 2000 installation from the Windows XP boot
menu, you just need to add a line to the Windows 2000 installation in
the boot.ini file (the one on the XP drive) and it will allow you to
dual boot with the Ntldr boot loader. There again, the Mount Manager's
drive letter assignment will still be respected and the booted
installation will retain its assigned drive letter. You can also boot
the Windows XP installation from the Windows 2000 boot menu, but to do
so you will have to replace the Windows 2000 version of the shared files
ntldr & NTDETECT.COM, the Windows 2000 version of these files cannot
boot the newer Windows XP, the XP version of the files can boot the
older Windows 2000.

John

 

[flahmeshess]

Thanks very much John ... and thanks Pegasus....

You can toggle the drives in the BIOS (without unplugging them) and the
installations will maintain their respective drive letter assignment
when they are booted, the Mount Manager's drive letter assignment is
persistent and it will be respected.

You can also boot the Windows 2000 installation from the Windows XP boot
menu, you just need to add a line to the Windows 2000 installation in
the boot.ini file (the one on the XP drive) and it will allow you to
dual boot with the Ntldr boot loader. There again, the Mount Manager's
drive letter assignment will still be respected and the booted
installation will retain its assigned drive letter. You can also boot
the Windows XP installation from the Windows 2000 boot menu, but to do
so you will have to replace the Windows 2000 version of the shared files
ntldr & NTDETECT.COM, the Windows 2000 version of these files cannot
boot the newer Windows XP, the XP version of the files can boot the
older Windows 2000.

John

 

[flahmeshess]

oh... one thought came to my mind...

is that case, should I have unplug my Win2K before I install my
WinXP ? Would I still be able to get the proper drive letter for
WinXP even thought the C, D, E drives are already assigned to Win2K ?

 

[John John (MVP)]

I don't quite follow here. I thought that the operating systems were
already installed and that they were installed independently of one another?

John

 

[Andy]

1. Connect the WinXP disk as the first one, i.e., the one that the
motherboard boots by default, and the Win2K disk as the second.
2. Boot into WinXP.
3.a. Edit boot.ini on the WinXP disk (Start > Run > c:\boot.ini).
3.b. Edit boot.ini on the Win2K disk (Start > Run > e:\boot.ini; I'm
assuming the Win2K disk is e:; if not, use the correct letter).
4. Copy the entry under [operating systems] from the Win2K boot.ini
and paste it in the WinXP boot.ini, changing rdisk(0) to rdisk(1).
5. Save WinXP boot.ini; exit Win2K boot.ini.

 

[Pegasus \(MVP\)]

1. Connect the WinXP disk as the first one, i.e., the one that the
motherboard boots by default, and the Win2K disk as the second.
2. Boot into WinXP.
3.a. Edit boot.ini on the WinXP disk (Start > Run > c:\boot.ini).
3.b. Edit boot.ini on the Win2K disk (Start > Run > e:\boot.ini; I'm
assuming the Win2K disk is e:; if not, use the correct letter).
4. Copy the entry under [operating systems] from the Win2K boot.ini
and paste it in the WinXP boot.ini, changing rdisk(0) to rdisk(1).
5. Save WinXP boot.ini; exit Win2K boot.ini.

This method will probably get Win2000 to run off drive letter G:,
which is exactly what the OP must avoid.

 

[flahmeshess]

Yes yes... already installed. I'm just wondering if I could have left
the Win2K HDD plug in while I install WinXP. Would I still be able to
install WinXP to the 2nd HDD but still install to C drive.

 

[John John (MVP)]

Yes, no, maybe... It depends on how the disk's active partition is
enumerated when the installation is done.

How Windows 2000 Assigns, Reserves, and Stores Drive Letters
http://support.microsoft.com/kb/234048

Overview of PNP enumeration and hard disk drive letter assignments in
Windows Server 2003 and Windows XP
http://support.microsoft.com/kb/825668/en-us

John

 

[flahmeshess]

OK. I manage to edit boot.ini on the XP side and boot up both 2k and
XP but:

- in XP, I have all the XP drive letters correct. 2K drive letters
are reassigned

- when I'm back in 2k, the 2k drive letters (C/D/E/Y) are correct but
the XP C/D/Z drives are not assigned any drive letters while the E
drive is assigned to F.

I cannot access the files in XP drives while I'm boot up as 2K. Is it
safe to assign a drive letter to the XP drives ?

Thanks very much.... very much appreciated.

 

[John John (MVP)]

Another twist in the plot, where did the drive letters Y & Z come from?
Do you have a pile of network (mapped) drives? Have you exhausted all
the available letters in the alphabet?

You can reassign the XP disk/drive letters while you are in Windows
2000, the drive letter change will only apply when you are using the
Windows 2000 installation, the letters assigned by Windows XP will be
maintained when you boot to XP. Use the Disk Management tool and see
what is going on there. You will/should not be able to reassign the
current "System Partition" drive letter, the current System Partition is
the one that holds ntldr, boot.ini & NTDETECT and that was used to boot
Windows, based on the information in your post that would be the "C:"
drive on the "XP side", it will be identified as "System" by the Disk
Management tool.

Note: The reason that you can reassign drive letters while not
affecting how the other operating system assigns drive letters lies in
the fact that Windows 2000/XP holds the drive letter assignment in the
registry at HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices. The Mount
Manager's drive letter assignments are persistent, when Windows is
booted the MountedDevices key is read and the previously assigned drives
letters are maintained and reassigned to the same drives. Each
installation has its own registry and each operating system will read
its own MountedDevices key when it boots, it will assign the drive
letters as read from the information in its own registry. In the boot
process, up to the point where the MountedDevices key is read, the
partitions have no drive letters, they are only device objects like
"\Device\Harddisk0\Partition0".

John

 

[flahmeshess]

OK. Now I understand better now. I can just assign the letters in
Win2k and use it.
Sorry for the twist in the plot. The Y & Z drive letters.... I didn't
think it was impt then.. I just create extra partitions which I name
it Y (or X... was change to Y due to the 2k->XP migration) and Z.

I normally put all my "temp" stuff in an X drive so that it does not
cause so much defragmentation in my data drive, when I delete the temp
stuff.

I also put a partition somewhere between my OS and Program partition
(which is C and D) and my data partition (which is E) and call it Z.
I then put the swapper in Z drive.

I also put the Firefox, Internet Explorer cache in the X or Z drive
(currently in X but I'm going to migrate to Z cause I'm going make use
of the user switch in XP).

Thank you John for all the help.

 

[John John (MVP)]

You're welcome.

John

OK. Now I understand better now. I can just assign the letters in
Win2k and use it.
Sorry for the twist in the plot. The Y & Z drive letters.... I didn't
think it was impt then.. I just create extra partitions which I name
it Y (or X... was change to Y due to the 2k->XP migration) and Z.

I normally put all my "temp" stuff in an X drive so that it does not
cause so much defragmentation in my data drive, when I delete the temp
stuff.

I also put a partition somewhere between my OS and Program partition
(which is C and D) and my data partition (which is E) and call it Z.
I then put the swapper in Z drive.

I also put the Firefox, Internet Explorer cache in the X or Z drive
(currently in X but I'm going to migrate to Z cause I'm going make use
of the user switch in XP).

Thank you John for all the help.