Microphone trouble in XPPro

Help,

I just upgraded to Win XP Pro on our HP Pavilian Notbook. The microphone worked before...now it does not. I've followed advice about how to enable the microphone but when I go to the master volume or sound controls there are no triggers for the microphone. the control panel has no configuration for a mic. When I look at the sound recorder window it appears to be recording. When I press the red stop button an error window pops up and informs me there is another applicaton recording sound. I have no other applications running that WOULD record sound.

any help?