I have just built a pc for someone to the following spec:- ASUS P6T deluxe; i7 920 processor; 12GB Corsair memory (6x2GB sticks) Radeon 4890 in crossfire; Windows 7 Ultimate, a nice spec. The problem I am having is that the system only recognises 8GB of memory, if I reseat the memory it will be recognised some of the time but often when I reboot it loses 4 GB of memory. The memory was a 12GB kit designed for use with an i7 system. Incidently, when I run the windows experience index the system crashes and reboots, the rest of the time it runs OK. Anyone any suggestions of the problem here.