Sodimm difference?

[MisterE12]

I have a laptop right now that takes sodimm 200 pin DDR PC3200 memory. Right now it has 2 sticks of 256 DDR PC3200 ram. It does run at DDR 400. Can I stick a DDR2 PC4200, 200 pin memory in it? Something tells me it's not the same, but had to ask.

Thanks for the help.