It's rather disappointing that your computer is so old. DDR3 memory is STILL at an all time low, and you would've been able to get 4GB for like $20. However, DDR2 memory is not that cheap right now -_-. If you want to shell out $50 or more on a memory upgrade, you can get 4GB of DDR2 memory (that memory I linked to should be what your board takes judging by your processor model).