What type of mouse are you running?
Is it an old "ball" type?
If so get rid of it... they are problem-prone
go for an optical mouse.
Fist thing I would try is another mouse-- mice are cheap.
get a good optical mouse-- like a logitech (any logitech)
Stay away from Microsoft mice.
Do you have any of the install discs for Windows ?
I also could be that there are some corrupted Windows (explorer) files-- sometimes malware-- and it's removal can damage system files.
If you can run a "system file check" see link below.
scannow sfc - LEARN how to use SFC.EXE (system file checker) in this article!