Black screen from amd unticked box

[Velonica]

Hello, i was wondering if someone could help me as i accidently unticked a box in the amd catalyst center (70mhz etc) and my screen went black and now i cannot use my computer at all, there is sounds but no visual help. Could somone help me please?

 

[ilysaml]

Connect your PC to a CRT monitor and then revert it back to 60 Hz or take your monitor to another PC and set the resolution to 1024*768.

 

[nukemaster]

Hit the F8(you can just hammer the key if you want after the bios post has past) key just before the windows splash screen and them select VGA mode or Low resolution 640 x 480 mode(Xp / Vista / 7) from the boot menu.

This will set everything to a really low screen resolution(everything will be huge) and should also set the refresh rate back to 60hz. Once in, just set it back to what you want.