NEW BUILD RUN A GAME THEN IT CRASHES BACK TO WINDOWS

[hiredhelp]

Hi All merry xmas .my problm im having is ive built up a computer .i have fitted a powercolor 512mb card in a asus p5q-e and i seem to have problems when booting into games it would freeze then flicker black then some games evntually go back to dsktop. this has happend on xp and on windows 7.i have tryed old and new drivers and a new 1gb ati powercolor vga card too. im at my wits end when i id a performance test in windows 7 it scan the direct 3d files some stage during them files of direct3D the monitor display went no signal.kinda like whn the games freezes after like 2 min starting them again this is a new build tested 2 cards on brand new other ived used in my rig for nearly a year fine power suply is 720watts hyper could it be the tft need help thanks guys...

 

[hiredhelp]

thanks for the reply
yes ive tested the latest drivers and old. for the vga i have tsted many games not just 1
and the cpu hasnt been over clocked nore the ram or vga. ive tryed reinstalling windows 3x windows 7 and once on win xp bios is up to date reads my ram and picks verything else up fine. im wondering if it could e a dodgy pci slot .
but if so why when i scan useing windows 7 performace test the monitor goes blank no signal when scanning D3d files im thinking thats to do with direct x... cheers

also forgive any spelling errors as i have a dodgy keyboard atm

 

[hiredhelp]

thanks for your input im unable to give a snapshot of everything witch is what i plan to do for you. cos its at my fathers as was for him.

PSU- is HIPER TYPE R MUDULAR 2 720 WATT not rubish Thoe i will edmit i bought this 2nd hand on ebay £60 evrything rest is new
BOARD IS A ASUS P5Q-E bios has been updated but evrything inc ram is left on auto. or default
vga is a powrcolor as stated 512mb also has got latest drivers and ive tryd old also tested my new 1gb powercolor card same issues.
Intel Core 2 Duo E6750 2.66GHZ/4m/1333 LGA775
RAM Kingston KHX8500D2BK2/2G Hyper X Limited Edition / 2GB / 1066MHz / DDR2
2 WESTERN DIGITAL DRIVES sata not raided
running 21" ben q

im thinking could be the psu but why dos it fail in win7 performance test scanning d3d files

when coms to the bios im first to edmit i dont like fidling too much maybe fsb bit but thats it but thats on mine my dads RIG has not en touched and has been reset too on the mobo.
cheers for all the feedback.

happy xmas glad when over my kids drained my pockets

 

[hiredhelp]

For a 512MB card, i'd guess its going to be a mid-high 3000 series, or a low 4000 series card..

yep i think tommorow ill go over thre check that ram out for now give him mine to run as for the card im sorry guys i thought i stated clarly the card 4870 feel it of a dohnut..iv also tstd the 4870 1gb and th 512 hes running now that was onc in my machine for nearly year running well but th powersupply couldnt cope with the 1gb 4870 i bought for him so he had mine 512 4870 once i get his rig back at mine ill start eliminating things. like the memory