Adding RAM Question

You should buy the same type of RAM. Buying RAM with different characteristics will only make it more difficult to make the system stable.

If you memory timings (Cas etc.) are set to AUTO, the slowest RAM's timings will be chosen, it shouldn't be a problem though, as I'm also running a mix of 2x1GB and 2x2GB RAM.

But you might not be running overclocked memory and that makes it easier.

Whichever type of ram you buy, to ensure stability the clocks and timings of the slowest should be used. So getting the same type would be best, or sticks with the same ratings and voltages. The voltages part is also important, because this will ensure stability.

There shouldn't be a problem with mixing 2GB and 1GB sticks if you want to go that way, but you could also just get one additional 2GB stick.

Yes, Ideally i would get the one 2gb stick, but i have not been able to find it in just a 2gb pack. I will keep looking in case i just missed it. Thanks for all the help guys.

if you already have 4gigs of ram you need a 64 bit os to upgrade

Yes ty i know i run vista prem 64 bit

Good Info There thank y0u