AFAIK, the only processors that give a damn about what RAM your motherboard uses (Provided you have the right socket and the right ram type) are the Intel i3/i5/i7 processors, as they only take DDR3 ram.
i have pantium 4 2.8 ghz processor ,it is compatible for ddr2 2gb ram or not .please give me solution
Is this a store bought system?
If so, make/model? (HP Pavilion, etc.)
The motherboard will dictate what type of RAM to use.
Until I build my new system, I'm currently also running with a P4 @ 3.6GHZ with DDR2 667.
Keep in mind that if you're running 32-bit Windows XP or another 32-bit OS, the max RAM it will see is 3.5GB, even if you have more installed.