What happens if you place a bootable Windows XP hard drive in a system with another existing boot drive?

sygyzy

Lifer
Oct 21, 2000
14,001
4
76
Last year I tried to backup/clone my primary hard drive and was unsuccessful. However, I thought it worked and to test it, I put the new drive and booted it up. When it got to the XP login screen it froze. For some reason, I decided to plug my original C drive back in (the source of the clone operation). I hadn't formatted it. I plugged it in as the primary slave. Anyway, the bootup worked. I had all my files and just assumed that it was using the new C drive. However, I soon realized that though the original drive was installed physically as a primary slave, it was being used as a primary boot drive. I thought that was really interesting. XP sort of "tracks" your drives and it doesn't matter where on the chain it sits. One of the reasons I decided to physically install the old drive back into the chain was so I can take my time copying over things like My Documents or anything I might have forgotten to backup.

My question is related: If I installed a fresh copy of XP on a brand new drive. Then installed it as the primary master (C) and then took my current hard drive with XP installed and installed it in the chain, how would XP handle that?
 

TGS

Golden Member
May 3, 2005
1,849
0
0
You will have two bootloaders installed, one on each disk.

If new drive (A) gets a fresh install of XP

and Old drive (B) still has a valid installation of XP, when you set your BIOS to boot off drive (A), you will only see drive (A)'s installation. When you set drive (B) to boot, you will only see drive (B)'s installation. Both will look like that by default. You can edit either disks boot.ini to reflect a seperate boot entry for each volume.

It's would seem like a waste to do an entry for each, as you would have to switch in the BIOS back and forth between booting from (A) to (B) rather than just making use of the boot.ini.

Having two bootable volumes will not hurt either installation, as you can only initialize one bootloader at a time. (IE the drive you pick to boot from (A) or (B) )
 

sygyzy

Lifer
Oct 21, 2000
14,001
4
76
So are you saying that if I boot off the new drive (A) and leave (B) installed, I won't see ANY of B's files?
 

TGS

Golden Member
May 3, 2005
1,849
0
0
You will have to take ownership of Drive (B) while booting off of drive (A). Even though (assuming here) you used the administrator account for permissions, the SID of the user will be different.

If you propagate permissions down, and just take ownership of the drive you should have full access to both volumes.
 

NogginBoink

Diamond Member
Feb 17, 2002
5,322
0
0
XP tracks drives (and assigns drive letters) based on a signature in the drive's MBR. So yes, XP will "track drives."

However, XP can't do this until the OS is booted. To boot the OS, the BIOS enumerates drives and loads sector 0 from the first drive it finds. So drive order matters for that phase of boot.