if it sees one too many hardware changes. But, generally when this happens, it ignores you when you return to the original configuration. My only other thought is that Windows during it's own memory check found the two modules not working well together. This might be remedied by installing either 1 512 meg module or two identical ones. Small performance variables exist with memory modules. What you might try to do is change these to more conservative settings in the BIOS if the memory is configured by SPD. Set the timings to a higher number and try that. Otherwise, I suspect one of two conditions above is possible.
I've had my second strange experience with memory in a week. Must be something in the air (does that expression really apply???)
Anyway I'm working on a Compaq PC with a Celeron 733. PC has all original equipment. I noticed it was a little light on memory (256MB) for what the owner wanted to do so I bought another stick of 256MB - both PC100.
I installed the memory and BIOS recognized the new total - 512MB. Then Windows XP wouldn't load.
The PC loads to a Windows option screen to boot into Safe Mode, Load Normally, Last Known Good Configuration etc. No matter which option I choose Windows won't load.
So I pulled both sticks of RAM and put one in slot one. Windows loaded. Then I did the same thing with the second stick of RAM. Windows loaded. Then I installed each one (separately)into the second slot and both times Windows loaded.
So . . . any idea why the system won't complete the boot process with two sticks of memory installed but can do it with either stick in either slot independently???
Thanks for the ideas,