I'm having problems trying to get a few more months out of an old pc. I've bought some more SD RAM (DIMM). There are 3 slots in the pc. It had - 1x256 and 2x64 chips in. I bought a 512. On replacing one of the 64s with the 512, i was told on bootuo that my ntfs driver is missing. if i swap them round within slots, sometimes i never get any life from it at all. I've tried various configurations but the only one that works is the original one! Is there a rule as to the order and sizes of SD Ram? I seem to remember that one form of ram required twin pairs of ram, but that cant be true as i've got 3 slots... Or any other helpful suggestions?