Previously installed ram was 2x2gb Kingstone Blu. I have an issue with ram i recently purchased I have a P7H55-M LE motherboard and recently purchased Patriot PSD34G13332 2x4gb. Both sticks work seperately. But not together, when both are used together I dont even reach the login screen and it comes up with blue screen. This is on windows 7 64bit OS. I have tried changing the ram speeds in the bios and that didnt do anything for me any suggestions?