Emachines T3304 Windows Xp diamond technology Microphone

so ive been recently building a e machines desk top pc for a while now and recently updated the sound buttt the chipset i installed didnt come with a microphone program ive had this computer since 2003 n ive always been able to talk on webcam b4 using my built in microphone n now i cant figure out how to get it to work again please help me!