The same thing has happened on two of my laptops running XP home. (Fully updated.) All recently. When I start up or try to switch accounts I get a pop window stating: "This computer is in use and has been locked. Only Acer/Lee or an administrator can unlock this computer." Then I get a form for inserting user name (which contains, "Lee" and asks for password. I have never pass worded these machines. As I said, the same thing happens when I try to switch to another account (using [Windows]+L) On one machine, I tried going to a restore point prior to this happening, but that did not happen.3 people need an answerI do too