I've had exactly the same problem, i think it first happened when i was repeatedly cancelling restart prompts after a windows update. It went when i restarted but has since come back and now never goes. I cant click anything on the taskbar and just get the default beep when i try.

is this right click only, or any click whatsoever? You've tried rebooting? If that didn't work, open my computer > right click on your system drive (whereever windows is, usually c) > properties > tools tab > check now button > tick the two boxes and click start > it will prompt you for a reboot, but you need to be aware that it will take a while depending on your hd size (could be up to or over an hour), so before you reboot, make sure you don't have to use the machine in the near future.....that will check the file structure to an extent, but it's not as deep as sfc....which will be the next step if that doesn't work.

thanks,

v