Emachine

[resteele32]

can i put ddr memory in a computer with ddr2

 

[electrontau]

No. They are not compatible. Different number of pins and voltage.

 

[C12Friedman]

No, the two are not interchangable since, among other things, they run at different voltages. The DDR stuff wouldn't fit and if it did somehow, it definately wouldn't run. Your best bet if wanting to add ram is to add it as a complete kit, you can use the tools provided by the ram manufacturers such as Crucial, Corsair, Kingston and GSkill to find compatible ram.
Hope it helps