How Do I Get My Computer's Audio Back?

I recently had a hard drive crash, and in desperation (because I'm broke) I decided to fix it myself by switching out the hard drive from my old emachine to the one I have now. It works ok, except that the audio doesn't work, and it keeps saying I need the right driver. But when I tried downloading and installing what I thought was the right driver, the computer went nuts, and I had to do a system restore. So where can I get the correct audio driver for emachines T2862?