Old computers had DDR, DDR2, DDR3 and new ones have DDR4. So for this RAM to fit, it has to be compatible. You can try it and see if it fits and works.
My old Acer died an early death. (thanks to my pet rabbit peeing on the keyboard & the acid affecting the motherboard)
I'm gonna assume none of it got to the 4GB of extra RAM I installed myself. I'm looking at a new HP. Would I be able to use it with the new one?