Drivers causing pc startup problems?

I've been having problems lately where I turn on my computer and it makes a few bleeps then switches itself off.
Anyway just now I needed to restart so I did and it did a similar thing to before, only this time the screen said 'no signal'. The computer restarted and carried on but the screen just went into standby. This leads me to think that both of these problems is caused by my graphics card, probably the drivers?
Could anyone help me, I'd appreciate any help.
Note: Im using forceware 77.72 drivers on an Asus en6600gt pciexpress card
Thanks

can you see the POST screen/bios menu? if not, then you have a hardware-related problem. if the post/bios comes up on your display, but when the windows boot loader kicks in the screen turns bloakc, then you can assume it's a driver problem.

if you have the latter, restart the computer in safe mode (press F8 when the windows boot loader starts (right after the post)), and you can uninstall/change your video driver.

I can see the bios screen at load up. This is what happens:
I switch my computer on it bleeps 2/3 times and turns off.
I turn on again, an Asus A8n-e motherboard picture comes up whilst it loads the first part of the bios (the one with the memory check i think), then it goes to the second bios screen which shows black with white text like normal.
After that the windows xp logo comes up, then my computer goes to the desktop.
I have now updated to some later drivers, forceware 77.77 and I still have the problem.

if your computer is shutting itself down when you try to power it on, you have a hardware problem. prime suspects include the mobo, psu.