I have a Compaq Presario 5838 desktop (purchased new in 1998). It came with a AMD Athlon K7 500MHz processor. I would like to upgrade the CPU to make it faster. I don't want to buy a new system. I spoke with HP and the mother board will only handle up to 1GHz speed. Would it be best to change the CPU to the AMD 1GHz "Thunderbird" or replace the mother board and faster CPU? I am currently running Win98 but will upgrade to XP in the near future.