Ja det är skillnad på PC och PC2 (kallas även DDR resp DDR2). Köp den rätta.
Men du borde inte kunnat kunnat stoppa i fel i minnessockeln då minnena har urgröpningen på olika ställen. Det fungerar inte alls.
"The 200-pin SO-DIMM has two variations for locating the notch which are nearly indistinguishable to the naked eye. If the notch is located further outboard, it indicates the DDR class of memory. When the notch is located nearer the center of the board, it indicates DDR2. These two types of memory are not interchangeable, and the different notch locations prevent incorrect installation."