Some programs (or components of them) automatically 'run in the background' when you start your computer. If a component of BearShare Music Lab is doing that, you won't be able to uninstall it because you can't uninstall a running program.
Try booting your computer into Safe Mode. (Press F8 during the boot process). The screen will probably look rather weird because the video driver won't be loaded but you'll still be able to access the option to uninstall the BearShare program.
Chris



