I CANT HEAR SOUND, OR USE MY MIC. please help!

After i did a reformat of my computer, i can no longer hear sound or use my mic. I've already done windows update, and got all of my devices working except the speakers and mic.

I have an emachines 512mb ram, win xp, amd 3200 cpu.

 

Could you please look on the front of your computer and look for the model number of your emachine. It should look something like T2875. Also please check the device manager, you can do this by right clicking on the My Computer icon and go to properties. Next go to the hardware tab, and click the option labeled device manager. Verify that there is nothing that is standing out with an exclimation point or red showing conflict or unknown devices.

Regards
Josh