|Not all memory is compatible with all systems and sometimes the difference between the two memory modules is too much for the system to compensate for. If the 1GB will not run by itself at all, then the memory is either bad, or is not compatible with your system. Chances are that the voltage, speed, latency, or other timings are not compatible with your motherboard. Put back the original memory and go to www.crucial.com and use their memory scanner to tell you what memory will fit your system and then compare all of these details to the memory you have. Purchase appropriate memory from where you like, but avoid used memory, especially from unknown or unrated sources. Your system will run better if the memory you purchase is in matched sets so both slots are filled with memory of identical specs and if your motherboard supports dual channel mode, will run even better this way.|
You have to be a little bit crazy to keep you from going insane.