Right now my computer has 256MB RAM (acutally its 240) i want to upgrade to 512. Do i buy another 256 chip and add it to my current 256 or do i take out the 256 and put in a 512. I am not the best with computers so sorry if this is a stupid question.
The brands never have to be the same. The specs of the ram card does. If that's the e-machines you refered to in the other post it most likely uses pc100 or pc133. You best look for the memory matrix at the makers web site or you might get stuck with a ram card you can't use.
Some boards like my old Biostar had to have certin sized cards in certin slots to get to a certin ram total.
And some machines will not see past a certin ram size. It's called upper ram limit.
Add on>>> As pc133 costs more these days than most DDR ram, I would sugget you get Everest and find out what's in there now. Save yourself a lot of grief. Do your homework first then buy.