unable to bring back to original setting

hello sir,

my name is praveen .

i have a problem with Window xp sp2.

when i changed the settings of display from 800*1200 to 1280*800 , it turned completly blank and the error is coming like sychronisation is out.
so ihave restarted the system but same display.

then ihave gone to safe mode and changed the setting back to original settings and restarted the system,still nothing changed and problem remains the same as sychronisation is out.

what is the best solution for my problem as iam facing the problem from last 8 days.

ihad asked lot of people but no proper answers from them. some people say you have to formate your system.
should i formate the system?

hoping the best solution from you.

I've never heard of 800*1200 resolution. That's rather impossible. I assume this is a laptop? Your resolution choices should be 1280*800 1280*768 1280*720 1280*600 1024*768 800*600

maybe its a tablet?