Windows 7: BSOD error, cannot start up

Hey,
I cannot start up windows 7. Because I can't start up windows 7 im afriad that means I cant get a system health report. I can't even run system restore from the boot cd.
As I attempt to boot up It either freezes completely, or sometimes I will get a BSOD with varying messages; atapi.sys error, IRQL not less than or equal, or corrupt PFN list.
RUnning windows 7 home premium 64bit on MA785GMT-UD2H mother board. I've had this computer built for just under a year now with absolutely no problems whatsoever, and I'm very careful with how i use it (also I don't play games/movies etc etc).

Any help would be mega appreciated. I just have no idea where I can go from here.