It is hard to pinpoint where the problem is from your discription but here are the things I would start with. Do a scan of the hard drive down to the physical level to find any bad sectors on the drive, check all cables to see if anything is loose, swap out the RAM to elliminate that as a problem. scan for viruses, spyware, and defrag your drive. Verify that all drivers are current. Check event viewer for any errors.

HOw is this PC positioned physically?

Getting good air flow?

It is getting hotter and as an admin the number one cause of locks ups are heat releated issues.

Open her up blow out any dust.

Check bios gettemp readings etc.

Celery's are CRAP processors udner heating conditions... should have splurged for AMD or true Pentium...

Here you go: http://www.theeldergeek.com/defragme..._page_file.htm

Most common problem with a slow PC in my experience is that the C:\ drive is too full.

On your system I'm guessing that 300mb should always be available.

Also run disk defrag from system tools.

May be worth formatting the drive and reinstalling windows if problems persist, depending on how old the current build is.

You may just be expircing the effects of time, tons of programs installed, tons of programs on startup, and a serrious lack of ram.

Can you tell us abit more about your computer? age, specs, programs installed? I need to breakout my W98 book I suppose

It's quite possible that dust has accumulated in the system. Along with what everything else suggested, I'd recommend inspecting your power supply fan, along with the processor's fan. Heat can definitely slow down a system-- I'd begin to suspect hardware since you indicated this happens outside of Windows.