So, what happened between the day you upgraded the memory and the next day? Did you turn off the PC at all? Was it running all night and then you found it wasn't on when you came to check it?When I install the memory sticks the pc works fine, the next day that's when it did not boot.
Source: http://www.tomshardware.com/answers/id-3504459/ram-crashing-syatem.htmlA few years ago I bout 4 sticks of 2GB ram and every time i use it my pc would BSOD and reboot :-( it is 2GB pc2-6400 800Mhz s/n 124922-0984
Source: http://repyxel.appspot.com/Memory-R...DDR2-800Mhz-PC2-6400-Low-Profile/122661699230(Warning : didn't work in one of my Intel machines - possibly AMD only - google S/N: 124922-0984)