First and formost: Perform a re-format of the hard drive and a complete reinstall of XP. It's the only way to be certain you have gotten rid of any hidden beasties that may be causing the system to hang or slow. It's extremely simple to do, and only takes a bit of time...no major software or programing experience required. Just back everything else up someplace first!
Second: Get more RAM. Just DO it. I'm surprised your video card even turns on with that little!
Does the dial-up modem still work too? he he he If your machine is as old as all that, you can very likely find RAM and next to nothing - or even free. It would take you all of about two minutes to put it in - maybe three if you can't find the right sized screwdriver to pull the side panel. Easy and fast.
Third: I would dump the anti-virus stuff. I've never had it catch much of anything worth catching in almost ten years. But it is almost always a M-A-J-O-R resource hog and will slow a system like yours to an absolute crawl I would expect. Unless you're in a position to need to be visiting questionable sites frequently, I would be very cautious about what programs I installed, and how active I allowed them to be - even in the background.
Whatever you end up doing...good luck!
