Not a great deal I'm afrain, you can upgrade the RAM thought to what degree depends on the motherboard. I would hazard to a max 256 of 512MB, the HDD upgrade no problem though the os would determine what size, 98 or millenium can handle large drives. That would be about as much that is worth upgrading. Better would be to invest in a cheap and cheerful new low budget pc. Look at Microdirect click here or somewhere similar.