Ok.....when I first got XP Pro and my computer was new, I had something very similar happen when trying to do the check disk and defrag. I would click on these functions from "my computer" and the machine would seem to just freeze up. Cntrl/alt/delete would shut down the process, so I never had to reboot. I eventually got defrag to run successfully from the programs/accessories/system tools menu. Once I defraged the drive (after installing a lot of software), the problem ceased. I also installed all the updates for XP, so it's hard to say exactly what eventually solved the problem. You could also visit the Microsoft forums. I know this issue was discussed there. It's just been so long ago, that I can't recall all the tips that were offered by their sysops.