It's more than likely a software driver issue.
First thing is to identify what sound card you have .... make model and version. (you may need to take the cover off the computer and have a look inside)
When you have identified the sound card you'll need to go to the manufacturers website and download the latest WIN ME driver for it.
Before you install the ME driver you need to ensure that you uninstall any other sound card driver that's currently on the system.
Hope this helps
EF Series I Manual XR6
XR8 & XR6 Owner's Club of Victoria Member