make sure your running the f4 bios. use cpu-z read the spd info of your ram. go into the bios and set the ram speed up to 1333 by hand. 1600 speed is on intel mb using xmp profile. amd mb dont have intel xmp profile. check that the ram you have is 1.5v or more. a lot of the older mb have issue with low power ram sticks. use a hirem boot cd boot from it run an anti virus scan and hd tune and hard drive test. I seen failing drives slowly lock up system before. you can also on hirem boot cd run memtest86 to see if your mb having issue with the ram. the other issue could be that cheap power supply with the new ram and cpu not holding and the system is locking up. also try another ps to see if the issue stop.