DISPLAY MODE not supported. Help with error!

I accidently changed the display settings to something high..then i clicked apply. Sadly its stuck there. I rebooted..nothing works! I tried safe mode..tried changing the settings to its original state..then after another unsuccessful reboot it worked for around 6 seconds..then i got "VIDEO MODE NOT SUPPORTED" grrrr!!!!!!!!!!!!!!!!

Welcome
Although success is less than definite, try a system restore.
http://www.vistax64.com/tutorials/76905-system-restore-how.html

Go back to a date 3 or 4 days before you tried to improve the settings.