I am just guessing here, since I have never tried this myself, but the first thing that you should do is check what kind of video in you have on your PC. My PC is a medialaptop so I am sure that I can do it somehow.

All you really have to figure out is how to connect video out from your VCR (either regular antenna, Scart or even S-Video if your VCR isn't too cheap) to a video/audio in on your PC. Your options will be on the outside of your graphics/video card and your sound card. Then use google to find software that will allow you to record it on your PC. Don't know if any free ones are available (probably some are)

(note S-Video while far superior in video does not support Audio)