Restart Problems

[Gunwitch]

Recently i've been getting reboot problems. My pc starts up when i reboot then the monitor goes blank and it all stops. It normally takes a few goes to get it to boot up properly.

If i switch it off at the psu and turn it back on again or leave it off overnight it'll start up fine.
What i did notice was it goes to the user account screen before desktop. I didn't set this up, but i looked at user accounts and found another account called Asp. which i promptly deleted as i never set it up either.
Oh i flashed my bios 2 weeks ago, went from having two monitors to one monitor, and installed a new leadtek 8600 graphics card.
Anti virus picked up nothing.
Any and all suggestions, tips, etc are welcome

[spiral out]

Might be a PSU problem have you tried another one?

[Gunwitch]

only have the one. Its an 650W Atrix Silent pPFC Power Supply
Wouldn't explain the account login though would it and i only bought it last september new.

[Gunwitch]

Still having problems, refuses to reboot properly, took me 5 minutes to start up this morning aswell.

I've run sandra soft and it says my chip should be more powerful and so should my memory