That depends entirely on what type of ram your other machine takes. Theoretically, DDR2 is compatible with any other DDR2, but that is not always the case. DDR2 has a specific notch pattern on the bottom, that will ONLY fit into a compatible DDR2 receiver on the main-board. However, you want to try to avoid mismatched speeds of ram (533mhz, 667mhz, 800mhz, etc...). Unfortunately, some machines require that ram be installed in matched pairs.
The scanner at crucial.com is a helpful tool. It will scan your machine, telling you what you currently have installed, and make suggestions for what you can add.
Hope this helps.
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