Have you looked into more RAM for the machine ? ?
If you travel to crucial.com you can enter your specs and it will tell you EXACTLY which type the machine will use.
You don't have to purchase it from them you can shop around for pricing...
256 will run XP but it will lag doing certain things.
I find 768 to be the sweet spot on modst machines....
Course more is always better.
its been acting up ever since my freind stayed over, a few weeks ago. so about 2 weeks.
This may be a different issue altogether.