Computer crashing, help:(

[sjruk]

My PC recently has started crashing all of the time sometimes crashing in dos before the OS has loaded. it started with crashing when i was playing games such as Starcraft 2, Heroes of Newerth, but recently has progressed and got worse by crashing nearly every boot up (if i get that far)

What i've tried;

changing my graphics card drivers to the drivers from the CD
Resetting the BIOS (by taking the battery out)
I ran MEMTEST which came up with 0 errors
reinstalled and updated my sound drivers.

I cant get my full system specs because well i cant boot up but from memory i have
Gtx 460 graphics card
ga-h55m-s2 mobo
intel i3 cpu
i forgot the brand of my PSU, i think its a Corsair.

everything was fine with the computer for a good few months i could play battlefield badcompany perfect. please help i will try get as much information as i can when my PC decides it'll boot up and i can run speccy

none of which are overclocked

 

[JMMD]

Are you getting blue screens or is the system just shutting down? Any info from any of the crashes? Have you checked the hard drive for errors? Have you tried a clean Windows install?

 

[sjruk]

No it just completely locks up during a crash. But if i do get it on and can play a game then it will freeze crash for a while with the last sound repeating constantly, no i havent checked for HDD errors yet, my brother just told me to uninstall my graphics card and try an older one, and no i havent dont a clean install of windows yet

oh also i checked all the connections, hdd, psu graphics card etc, they're all in place just fine

finally i got my pc to turn on and instally speccy my specs are;

Windows XP Home 32-Bit
Intel Core i3 540 @ 3.07ghz, running at 27 degrees
2.0GB Single Channel DDR3 @ 666MHz
Gigabyte H55M-S2 Socket 1156
Nvidia GeForce GTX 460
244GB Western Digital WDC SATA HDD
Atapi iHAS124
TSSTcorp CDDVDW SH-S2223F
Nvidia High Definition Audio