Here's the story. I had Windows XP on my original 500GB disk in my computer. We will call this DISK XP. I bought a new 1TB drive and bought Windows 7 64bit to put on it. Call this one DISK W7. I just recently moved all my old files from DISK XP to DISK W7 so I decided I wanted to format DISK XP to make full use of it. Before doing this I always got a selection to load either XP or WIN7 from a boot menu. Here's the problem. I go to format DISK XP and restart. Now upon reloading I got bootmgr is missing from the DISK XP drive when only that is in and some other error saying the no system disk is inserted when I put the DISK W7 in only. I loaded Windows 7 onto DISK XP and am posting from it now. When in Windows here, I see my other disk and can access all the files. Now, what in the world happened and how can I restore my DISK W7 to work and load normally without reinstalling Windows on it and/or reformatting. I have 900GB of data on that drive I cannot lose and would prefer to not have to manually reload all of it.