Switching Hardrives leads to Invalid boot Disk

OK, So I have my computer and my girlfriends. My Motherboard is a Ga-K8nnxp
and hers is a Ga-K8U, I have my computer configured fine, works perfectly. But What I want to do, is to switch my hardrive over to her machine, and her's to mine. But when I put mine in into hers, making sure everything is hooked up right, cables, and set to Master, it shows up in the bios alright. But when I start it up, it gets to verifying DMI pool data, and it ends up saying invalid boot disk, please replace with boot disk and ect. ect.

Also it is try's to do some pre boot check, I need to do it again to see what it is, but its some nvidia adapter crap. I have the Drive Disk (western digital) and ive booted from that, but its scratched up pretty good and when I try to run the data lifeguard it has an error and takes me back out to the cd's menu. The drive is already formatted and everything, I can bring it right back over to my machine and it starts up flawlessly. I guess my question is what could be keeping it from going right into windows and starting up? I dont want to lose all the data on it by reformatting, and there's not awhole lot of options in the Bios to choose from, ive tinkered with the settings with no result. And you know how worthless the manuals are that come with motherboards.

Is it windows maybe that just doesnt recognize all the new parts on the computer? I cant remember the key command for safe mode, i though ti was F8 and i tried that F5 but it still doesnt get past dmi pool data.

 

Unless your HD has all the drivers required for her MB your HD will cause the system to crash as a master drive, now if you put your HD into her machine as a slave you should have know problems. Thats the way I see it from what I have read of your post. Hope that helps

PS:- Her HD should do the same on your system