Is your Windows Vista or Windows 7 stuck in a startup repair loop? Does your computer attempt to complete the repair request but ends up failing? There are a few ways to fix this.
Perform a chkdsk /r using a Windows Vista or Windows 7 disk under the command prompt.
Fix the master boot record and boot sequence by typing bootrec.exe /fixboot and bootrec.exe /fixmbr using a Windows Vista or Windows 7 disc under the comamnd prompt
If neither of these worked, please leave a comment and I can assist you some other way!