My RAM does not fit in my mother board

[Eliasu]

I have MSI B75MA-P45 mother board and Kingston ValueR DDR3 RAM.
They fit fine,but i took my RAM from må old pc and tried to fit them into my motherboard and they didnt fit.I searched on internet to see if there was 2 diffrent sizes of ram bricks and i didnt really find anything...My Kingston ValueR DDR3 ares smaller than my old ones but is there 2 diffrent sizes or am i doing something wrong?
I know this questing should be in the memory category but i dont know how to change it

 

[Onus]

Is the old RAM DDR2? It is not interchangeable with DDR3.

 

[Eliasu]

okey thanks it was the wrong type