installed my 512MB DDR2 667MHz CL4 240PIN Industry Standard DiMM i believe its a PC2-5300. My computer works on a PC2-4200 533MHz. when i installed the PC2-5300 the fan kept spinning loud and wont stop unless press the power button. why is this?
If it works fine when removing the PC2-5300 RAM, then it might not support it or you bought incompatible RAM for your PC. Can you provide more info on the PC and the RAM that you bought? Is the correct RAM for that PC still available?