I randomly lose the ability to right click on the desktop and access my computer and my documents. If Im in an application, like firefox the File button Edit History etc are all disabled. It starts by making the windows error noise repeatedly then stops. I have to reboot the computer to fix it. I have tried system restore, reinstalling xp running the latest virus/spyware/adware/malware programs. They found nothing. All of my system temps are normal. Any ideas?