I'm probably going in the wrong direction with this, but whats your OS? (ie: Windows 98, Windows 2000, etc.) Also, would you happen to have the installation CD for it? With Windows 2000 and Windows XP, if you have the installation CD, you should be able to "repair" the operating system. With Windows 98 and Windows ME you can choose to reinstall without formatting, I forgot the exact options, but during reinstall it should ask if you want to save your Program Files and etc. It would probably be better to either get someone who can do it themselves right there, or to look up a topic about it from a tech support board on another site, I don't think I could fully explain the process.

Either way, more than likely its an issue with your OS and not the file itself.