After a while (under 1 hour) of computer uses, it slows down to a halt. I pressed ctrl+alt+del and it shows that explorer.exe is taking up a lot of memory. Also CPU is runnign ta full load. I have checked with spybot, adaware, windows spy scanner and Norton AV 2004. Found absolutely nothing. Please, I need some help with this issue and if possible without reformatting.

Xp itself is a resource intensive operating system. You can do some things to fix this common problem. One is to streamline the services. Another is to disable what doesn't need to start up at boot up. A word of caution here. The services are so inter-related you have to be really careful what you do. You can lock yourself out of your system if you turn the wrong one off. As for msconfig, I would suggest other than the desktop and your anti viral software you uncheck most of what's in there. Doing that just makes the system take a tad bit longer to load those programs. I unchecked all the AOL stuff in my msconfig and that alone makes it zip right along. Check out www.blackviper.com for good no BS advice on what you can and can't turn off in the services. And that's just for starters. www.ccleaner.com has a good little program to clean up those useless dribbles of junk data on the drive. Defragging on a reular basis never hurts either. This is just a few things you can do but my fingers are starting to get numb from typing. Some of the others in here will have other suggestions. I may be crazy, but I'm not stupid...