New build trouble

[Graeme43]

Hi, just put together new pc in sig

On first boot it worked fine, showing ram at 533mhz and CPU clock at 9x200

Thing is on second boot it doesn't work sits at blank screen with fans on full and the display saying C1 something to do with ram

Anyone know how to fix this?

Thanks

 

[Graeme43]

system first boots ram at 533mhz then changes to 800mhz second boot = why no boot ram is 800mhz wth