Also, if the sound card (well, it's chips in the laptop but folk call it a sound card) has failed, try this few dollar thing. Link to follow.
If you are into troubleshooting PCs, this gives us a quick way to test the PC to see if it's the PC or the sound card.
So I have an atr-3350 microphone and I have the volume fixed, but the sound sounds SUPER digitized (like a bad skype connection). I am using this mic connected to my 3.5mm jack on a windows 7 laptop. Any suggestions?