dual booted p/c xp/windows 7 system won't boot to windows 7

Hi I need some help with a dual booted system. I have windows XP and Windows 7 pro 32-bit on my work computer. I came back to work after the holidays and was unable to boot into windows 7. I put in the windows install disk and tried to reinstall the software but the disk just try's to repair the disk. "fixing sectors this may take over 1 HR" this was started at 9:00 am ran all day when I...