If you have your Windows disc, can you do a "repair install," where it reinstalls Windows without deleting your files
Or if that doesn't work, you could try to install Linux on a USB stick or something and boot your computer with that, then try to copy all the files to an external hard drive using the Linux OS and then you could do a "full reformat" and reinstall Windows and stuff after.
http://www.lifehacker.com.au/2011/03...your-computer/