Hi Golfnut, and welcome to BleepingComputer.
If you are running XP on 128MB of RAM I'm not surprised that it is slow. With that little amount of memory some applications could take a long time to execute. Most will agree that XP needs a minimum of 512MB of RAM to start to run properly, 1GB will get it humming along. There may be some applications running that you don't need that can be shut down, but the best and easiest way to speed this up will be to add more RAM.
I just did a quick look and that is an older ThinkPad, it has two expansion slots with a maximum of 256MB per slot of PC133. Module this old are going to be dear in price.
By the way, Crucial wants $49.99 for one 256MB module.
Edited by dc3, 23 April 2008 - 11:22 AM.