Sometimes RAM may physically fit in the slot but may not be compatible. It will say something like PC6400 or DDR3-10600 etc which indicates what speed it runs at. Memory should ideally be matched but usually fitting RAM that runs at a faster speed in a slower laptop works e.g PC6400 will work in PC5300 system but not the other way round.
If the RAM physically fits at least it's the same type, as DDR2, DDR3 and DDR4 all use different slots and are physically incompatible.
Laptops are more finicky over what RAM you put in them than desktops and some brands (although this is going back some time) will only work with RAM with specific latency timings. This is indicated by 3 or 4 numbers separated by dashes e.g 3-4-3 or 2-2-2.
Please tell us what your existing RAM is and what you intend to fit.
Last edited by Arokh; 23/08/18 05:03 PM. Reason: spelling mistakes