I Have a Celeron running at 450 Windows 98, normal ancilliaries, working perfectly except, 64M memory, 3.3V unbuffered normal stuff. But I wanted to add a further 128m so Bought the genuine article from compaq, 3.3V unbuffered SDRAMM etc looks the same!, tried it in all 3 slots on the ASUS motherboard. PC could not see it. tried all combinations, and only the 64M could be seen not 196M. Took out the 64M and left the 128M in and now I have 128M fully functional. Can they not be mixed? do I swap the 64 M for another 128M or will it not see that also.