BleepingComputer.com: Microphone used to work, but no longer does

I have a custom built machine that I made in 2006. I have Windows XP (with all of the latest updates) etc etc. Back in May, I had to reformat my hard drive for various reasons. Ever since then, my headpone/microphone combo ceased to work properly. The headphone portion still works just fine, but I can't get the microphone to do anything other than produce static. This past weekend I went to Office Depot and bought a brand new headphone/microphone combo thinking that maybe I damaged the old cord somehow. Alas, it was the same thing, new product.

I have tried to go through all of the possible settings to make sure the microphone settings are turned on etc. Is it possible for the plug-in on my computer to go bad? Did I just miss an obvious driver download when I reformatted the hard drive? I have all of the specifics to what is in my computer at home (I'm at work now) and if this is necessary, then let me know and I'll gather that up tonight.

Anyways, thanks for your help in advance!

Wild Bill