Locked out of Windows

I have a Dell Optiplex 745 with Windows Vista Business OS.

I was attempting to fill out the screen horizontally and now get a error message "Out of range". I get that message on a black screen with no way of undoing the setting that caused the problem.

When I reboot, the same error message is posted after the logo is displayed. I even get that error message in safe mode.

Is there a setting in Bios that would remedy this problem? I am able to get the Bios setup.

 

Thank you Major Attitude for your support. I couldn't get into safe mode. The error message was there even in safe mode.
I resolved the problem by switching monitors. It works now but with a smaller screen.

Thanks again for your efforts.

Bronx Born