I am running XP home addition. If I use the switch user instead of a full log-off of one user before starting the other, I get nothing but a black screen with a cursor. The mouse does control the cursor, so it appears to be a video driver rather than a "locked up" condition. I have run Spybot and Ewido, so I don't believe it is virus driven. The black screen occurs when I click on the second user. If I do a full log-off/log-on, all seems to go normally. Any suggestions? Thanks