Welcome to bleepingcomputer!
First, I would uninstall your old sounds drivers completely by going to control panel, system, hardware tab, device manager. Once device manager opens, go to the sounds device and click on it. A drop down of whatever your sound card is called should come down. Now, right click on this and uninstall it. You will probably have to restart your computer after this. Afterwards go here: http://www.emachines.com/support/product_s...amp;model=T2200
and download and install the sound drivers.
If you are still having problems, have you checked to see if it's not the speakers at fault? Try a different pair with your computer if you can.
"I think there is a world market for maybe five computers." - Thomas Watson, Chairman of IBM, 1943