I'm trying to upgrade my girlfriend's computer by adding more RAM or replacing her 256MB one.

By adding another RAM into her computer does both of the RAMs have to have the same speed? I remember a friend telling me both RAMs have to have the same something..

If they are different speeds all will revert to the lowest.

It is best to match speeds and also brands.

The best is to have identical sticks.

It might be best to replace all of it with a newly matched pair.

Depending on the slot type and speed there are some really great values here:

http://www.newegg.com/Product/Produc...e=2GB+(2+x+1GB)

If you do not know the specs on the current RAM you can run this scan:

http://www.crucial.com/systemscanner/

Oh okay, thanks I just had an extra RAM lying around, so I was planning to use install it on the PC. But everything is different. So I guess I'll just plug that one in and take the original out.

Thanks.

No problem. Let us know if we can help further.