I'm using XP Home which has been very stable until a few days ago when, each time I used Windows Explorer or 'explored' files through My Computer, I received a pop-up warning 'Explorer has encountered a problem and must close'.
I was then returned to my desktop, the desktop icons briefly disappeared and returned and then I continued working.
In some cases, though, the PC froze entirely and I had no option but to re-boot to get it working again.
On behalf of Mankster (apologies if your still about) SFC will search for missing and corrupted system files and either repair them or replace them from your installation disk. Do you have a repair/reload disk or a full installation XP disk