Windows Cannot Find Bootable Drive

Hey guys, long time lurker running into a problem which has me at wit's end..

This afternoon I put a secondary hard drive into my PC running Windows 7 Ultimate x64. My goal was to load a friend's copy of Windows XP onto the drive so he could boot in his PC. Everything looked like it worked fine, I was able to go through the entire setup process and boot to the desktop without a hiccup. I removed the second hard drive from my PC and rebooted.

Upon restarting my own PC with my hard drive only, I ran into an error. The system powers on normally until it attempts to load Windows. I'm getting an error that's more or less telling me that my computer can't seem to find a bootable drive. Windows will not load and I'm forced to restart. I've gone into the BIOS, it sees the drive there. I've ran the windows XP recovery disc, and it sees the partition as well.

I've reset CMOS by pulling the little battery out and replacing it, restored BIOS settings to default, and disconnected and reconnected almost every piece of hardware. I even tried plugging in the drive to another SATA port. Still getting the error. I'm by no means a professional, but I've built a few systems before as well as switched out parts in older PCs for a few years. I've never encountered something like this and I'm basically out of ideas.

Can anyone here offer some insight into this? I'm frantically searching for my own Win7 recovery disc but I've recently moved and I can't seem to find which box it's in.

I'm hoping there's a solution to this that I'm overlooking somehow.. Unfortunately, I haven't backed up my drive so I would hate to reformat.

Thanks in advance.

try booting with your (Windows 7 Ultimate x64) disk and do a system repair..

scrooge

Alright. I'll continue searching for it. I'm guessing this is the only way to address the problem.