If you're dubbing your old LPs or from a video cassette, then the Windows program you need to use is Sound Recorder.

It's found in the ProgramsAccessoriesEntertainment menu off the Start thing and it's good for recording simple sounds, but it can only record a 60 second blurp. Alas.

To increase the amount of time Sound Record can record, you have to use the EditInsert File trick, described on the Microsoft support page:

http://support.microsoft.com/default.aspx?scid=kb;en-us;Q82215

Doing this trick can increase the amount of sound recording time in 60 second chunks. I recommend creating a BLANK.WAV file (as I've done below) that's about 300 seconds long or worth 5 minutes of recording time. Then you can use it to record longer chunks of sound, as described in my books and on the Microsoft support page.