Your icons change too? When opening an application like Corel Draw 8 or any big program you see strange comments like FONTS NOT INSTALLED ?
It has nothing to do with your hardware! It is one of the nice programs on your PC which leaks memory. Maybe Outlook Express (took me 2 months to isolate it) or any other freebie you find on the net.
There are RAM defragmenter on the market, they look nice, they help a bit but, no real solution.
Try to start your PC with less programs.
Anytime I start my PC, all is fine, starting Outlook 2000 , everything is fine, starting the newsreader (the tailored Outlook Express), things are getting nasty and after finishing my work on the news side I have to reboot....
Due to certain reasons I cannot swap to another application, so I have to live with it, but don't look at your hardware only....