My windows 7 pc does not recognize my microphone at all but my sisters laptop do

[bigbigcars]

i have an A4 tech microphone headset and a senic microphone headset, the headsets work great but the microphone is not recognized at all , even though every laptop in the house works with it well . how do i fix this?

 

[leandrodafontoura]

Is it the same OS on both machines?

 

[JacobTi]

Its a configuration issue.. re-configure sounds settings.

i have the same problem, i have apple headphones with one cable to connect into either the mic slot or headphone slot.
these headphones record sound.
They worked for about a week and now the mic has just stopped recording They work fine and record on my ipod
what do i do??