Old laptop RAM question

Can use you PC100 (100Mhz) RAM in an older laptop that goes up to 66Mhz? Would it just run it slower or would it just not work? I'm going ebay shopping so I'm just making sure. Thanks!

It should just run slower. I upgraded RAM in an old IBM ThinkPad Pentium 233MHz with PC100 (the P-233MHz uses a 66Mhz FSB), and it just clocked the memory lower. Hope you get where you're trying to go with your RAM upgrade!

Sweet, thanks for the advice!

Ram is all I need to get running sweet.