In old pc like pentium 1, 2 & 3 u can found 4 RAM slot but in pentium 4 there is only 2 RAM slot.

ahmmm.....actually its just commmon for a motherboard to have a 4 DIMM slot/RAM slot....it defends on your motherboard....it defends on the brand of your motherboard..i suggest before you buy a new motherboard,look for its RAM slots or the better ask before you buy new.....

different motherboards have different amount of slots. All netbooks nad most notebooks these have 2 RAM slots. Desktop motherboards usually tend to have 4 ram slots these days, unless you have a pretty old motherboard. You can open up your desktop/notebook and easily find out how many slots you have or you can refer to your manual if you still kept it!