I dont know about this computer (it's a friends) but I want to upgrade the RAM.

Right now it has KVR-400X64C3A/512 - 512Mb DDR PC3200

A link to the product is here for more info: http://www.vdhsoft.be/specs/21633.htm

That is one of the RAM sticks in there right now. The other RAM stick in there is a RENDITION 512Mb DDR. I'm unfamiliar with the brand, but I've always liked Kingston, fwiw.

Anyways, the motherboard has 2 extra slots available. I simply don't know what the motherboard model or make is. The computer is running winXP and overall it's a bit sluggish. It could probably benefit from a reformat but theres just so much on it that I think this is more reasonable to get done in the next couple weeks.

My question is, what's the best bang for the buck to increase the RAM on this computer? Ideally I'd like to put a 1GB stick in each slot, but I'm not sure what you can do to mix and match RAM. For example, the ddr stuff is so much more expensive than the ddr2 stuff on newegg. Can I use ddr2 instead?

I'd really appreciate your help in getting this problem handled and finding out just what I can do to speed up this computer. Thank you.