Musical Chairs For Hard Drives

I just started looking for drive space to shuffle some data around, and realizing that I hadn't booted into XP for quite some time, I attempted to do so. However, instead of booting XP, I booted into W7. Not only just any W7, but exactly the same as I normally use, even though the XP and W7 partitions are on two different drives. The only difference between them is the XP boot only offers the Administrator login, while W7 also has a user account option. Yet, I do not have any kind of RAID configuration.

I would have thought that I had installed W7 on both drives, and had forgotten, yet that would not account for the fact that both desktops look exactly the same, even the sticky note that I had put on it just a few days ago.

Computer Management identifies the XP drive as being XP, as well as HD Tune, but opening the partition with a file manager only shows $RECYCLE.BIN and System Volume Information.

I scratched my head over this for a while, and I "think" I remembered the XP OS going heads up, and that I didn't take the time to reinstall it...maybe. However, whenever I do install an OS, I always do so with all other drives disconnected, so there shouldn't be any problem with the boot manager being corrupted.

Trying to think of any other possible reason for the booting issue, I remember starting to set the XP drive for AHCI, but I didn't finish it, except to set it in the BIOS, not in the OSs.

Would setting it in the BIOS only, cause it to boot to W7, regardless of the boot choice taken on the boot menu?

When you use a boot menu in the bios... and the computer doesn't like the idea of booting to the drive you selected, it will go down the order and find the next one in line that it likes...

Sounds like something changed on your XP install like you said, so instead of booting to that drive you selected it just opted to boot to your normal Win 7 install....

Yes, I would agree with that, except if it were the case, then the login options should be the same either way, instead of only an admin login for the XP drive, and admin and user login for the W7 drive.