i recently built a new computer - ati5850 4gb ddr3 ram2000mhz intel 17930 2.8ghz 650w power supply and installed windows 7 64 bit on it.P6tSE motherboard. when it boots up it flickers and then goes to the login screen which isn't much of a problem but may be part of the bigger problem. all my games are 32bit and when i play them sometimes they run perfectly fine and other they just crash/ or pause for 15 seconds and then start working again.also twice while i have been on the internet flashplayer has crashed and i have had to reload pages. Also i got the bluescreen of death for no reason? not even playing a game at one of those times? would it be a problem qith my gpu? psu? or os 64bit?
Check your memory. Check your bios and make sure the timings and voltages match the manufacture's settings of your memory, Sometimes auto will not work. Also try reseating you memory on the mother board and while doing that make sure that you put the memory in the correct slots. you can also run memtest overnight to check for memory issues. I would also list what make model of power supply you have that could be important to troubleshooting the pc.
i downloaded mem tester and am checking to see if that is the problem. it is at 55% and has discovered 74 errors, wait 75. i will take it back to the store and get some new ram and see if that helps. thanks heaps for your help.