A few weeks back when exiting a game I found my desktop image disappeared and was replaced with a blue background. I right-clicked and changed background picture back to what it was and it seemed to fix it. Hasn't happened since. However whenever I get a prompt requiring my password (to authorize something) the box and it's buttons appear to be empty and the little wheel just spins and spins. So I can't enter my password. Any ideas what could be causing this and how I can fix it? Thanks.