I really like my ThinkPad. I have an R50e. It's not perfect, but I got one of the cheapest models available when I bought it and it really performs quite well for me. One thing I've run into recently, ...
If I remember correctly, you use the FN and page up/page down for volume, and FN and backspace for mute. That changes the volume for everything - windows and system sounds.
The first thing that you should do is disconnect all your peripherals. This is one of the possible causes of this issue. If after disconnecting the peripheral devices, the beeping sound stops, one of ...