Memory and Motherboards

Recently a friend asked me why 4 gb of DDR2 ram would not work in his motherboard. I took a look at the PC and after troubleshooting found that the DDR2 ram was fine. Lowering the speed of the memory in the BIOs allowed 4gb to bootup but with multiple errors. I took 4gb of another manufacturer's memory of the same speed and swapped the modules. Problem resolved. If memory manufacturer's adhere to a single standard there is really no excuse for memory NOT to work in a particular motherboard. However that is more of a dream than what really works in reality. Therefore it behooves you to check the motherboard manufacturer's website and user's manual for compatible memory modules before you buy your initial or additional memory. Or you can also check the memory manufacturer's website to see if the modules are compatible.