That's your problem. You need preferably 512MB for XP to be comfortable.
Belarc should have told you what spare slots you have and also your motherboard model. If you click here and enter the information about your PC in the Crucial Memory Advisor? Tool it will tell you what memory would be suitable.
the scan tells me I have the following memory: Slot1: 128MB non parity SDRAM PC133 Slot2: 64MB non parity SDRAM PC100 2 SPARE SLOTS Max memory capacity 512MB. It doesn't give me a suitable upgrade option because it can't find the model . although the manufacturer is Silicon Graphics ?
right click your desktop,go to properties,and in thenes and appearance,choose windows classic.wont make a huge difference but every little helps.also choose a blank desktop as it takes time to load a picture one.there are other ways ie changing what programs start up and run in the background.dont know if you want to go into that,if you do then i`ll try to explain it.