Alright. Try running ScanDisk first (not Microsoft Security Essentials, ScanDisk is a program for detecting/fixing problems with drives). You can do that by right clicking on your hard drive in My Computer, Properties, Tools tab, and then Check for Errors (or similar). Tell it to automatically fix file system errors and scan for and attempt recovery of bad sectors. Run it. It should tell you if there are any problems it can find, and if it can fix them. If it can't fix it, try reformatting it.
If you ever need a recovery program, Recuva works very well. I used it on my neighbor's failing hard drive, and it was able to get all the data off of it easily. It is completely free to use.
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Zachnorn Everything = overrated.
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