One way is to look at the stick of RAM and see if there is a label on it?it should mention what type of RAM it is or at the very least a model number. You can run that through an internet search to find out more about it.

Another way is to use the free program Everest, which can identify the RAM by make, model, speed, and performance. However, this requires that the computer be running, and running Windows. If the computer is unusable and you just have the parts then you have to fall back on inspecting the stick for clues.

On a side note, if you can match sticks of RAM p with a compatible computer, I?d suggest then running memtest86, a free utility that can test the RAM and ensure that it is functional.

Hope this helps,
John