Ahh but that is not what you said.
You said to format the drive and reinstall. That means you would lose the info. To keep it on a seperate drive is not gonna server you any purpose as after you format you cant just move the stuff back and expect it to work.
Any which wa you look at it you need a disc to install the OS. Just moving it will do nothing but corrupt your system even more.
How is there a cuorrupted file? If that is the case run chkdsk on your drive as a fresh install should not have corrupted files unless there is something wrong with the drive in the first place.