Hi, I have a few older systems. Ones an old gateway PII and another hp that is roughly 3 years old. I know the old gateway takes PC ram but does it matter what type I put in? If it put PC133 in and it is supposed to be PC100 can it still work??
You may have some trouble. OEM's like Gateway, Compaq and Hewlett Packard sometimes used slightly non-standard memory. They probably saved a couple of dollars over the industry standard per box. The memory guide at http://www.crucial.com/ can at least tell you if it takes a standard model or something dedicated to that manufacturer and model.
If they do take standard memory, you can find PC133 that will also work at PC100 speeds, but there are also modules out there that are PC133 only.
PC133 will usually run at PC100. Give it a shot and see (if you already have the RAM.) I've run PC133 at PC100 speeds in many systems in the past. In addition, Dell and Gateway generally use/used Intel motherboards back in those days, and if you have generic mainstream compatible RAM, it will most likely work.
One way to check it out is to use Crucial's memory finder for your specific system as Graphic67 said. Then look up the same memory by type and see if the part number is the same. If they are, chances are the board can take generic RAM.
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