What microphone do you use at the moment?
This would look to be the problem, otherwise it is the recording hardware that could be at fault.
Also what do you connect your mic into? is it a sound card or motherboard audio?
have you tried this:
Control Panel -> Sounds and Audio Devices -> Hardware Tab (Pick the one that relates to audio, I use Realtek so that's what mine says).
Click on properties for the one you selected, click onto the Drivers tab, and choose 'update driver' , then follow the on-screen instructions.