There is a lot more out there than viruses.
As mentioned in an earlier post, I've been given the task of going through the school's lab computers (40 PCs, all XP Pro) and cleaning out what students have saved, as well as setting everything back to ''default'' (or close to it).
I have now found that several machines' Control Panels freeze: the panel opens okay, but any further clicking where a new window does not open -- User Accounts, Printer, etc. -- doesn't work. The mouse pointer does not change to the friendly hand over the links, and further clicking gives me the busy signal. Then it just sits, with no response. I ran Trend Micro's Housecall, but that did not illuminate the problem.
Can anyone suggest something to try?