I use to be able to but it got disconnected and I'm not sure how to do any of that, so please, if you help her, you help me, and isnt that nice to help out us both at the same help thread?
While it would help to know what kind of microphone you're using, if it's just a plug-and-go sort of microphone (i.e.: No special software came with it.), then all you need is a pogram to actually record with.
Windows comes with the Sound Recorder program, all you have to do with it is connect your microphone, open Sound Recorder (should be under Entertainment when you open your Start menu), and click the record button. Then talk into your microphone. Sound Recorder records a full minute if I remmeber correctly--it's not the best but it gets the job done.
If, for some reason the entertainment folder was deleted from your Start Menu, you could also open it by Start-->Run... and typing in sndrec32. Or you could download a more advanced program like Audacity and record with that.