I recently installed Windows 7 x64. When I plugged in my external USB drive, it brought up the scan disk box and said I should check for errors. Ran it, and later I found some of my folders/files were corrupted. Tried a couple unerase utilities to get my critical info back, and failed. So, I ran scandisk again. Now almost all the files read as corrupted and it asks me to format the hard drive. Help!