Vista not booting
So I needed to do some hard drive switching with my computers. I had Vista installed on a 320gb drive in my main computer and there was an extra 750gb in there with videos/music/etc. on it. I copied the stuff I wanted to keep from my 750 onto my 320. Then I formatted and installed Vista Ultimate onto the 750 (Old Vista and other files now all on my 320). Everything boots fine and I move my files back onto the 750 with my fresh install of Vista. I go ahead and format my 320 and take it out and put it into my 2nd computer which I install XP on.
Now when I start my 1st computer (with the 750), it says "disk boot failure, insert system disk and press enter". I figured since I took out the 320 with my original Vista copy on it, I somehow messed up the MBR, so I put in my Vista disc and attempted the "repair your computer" option, however it doesn't list any OS in the box! The hard drive isn't corrupt... I can still see the partitions and files and everything, so it's not that. Any idea how I can fix this?
UPDATE: I've been messing with the command prompt on the Vista installation disc. I've tried "Bootrec.exe" but it doesn't seem to help much. /fixboot just says "Element not found" and /rebuildbcd gives the same end result. The weird thing is, it DOES find my OS as "D:\Windows" but yet it acts like it doesn't exist. What is going on?!?!?!