Try this.  Go to Start, Run and type:  Msconfig    Press Enter.  Click
Selective Startup and then remove the check marks from Config.sys,
Autoexec.bat and Startup items.  Now exit and restart your system when
prompted.  On the next boot, try changing your display properties.

It's possible that something loading at Startup is causing your problem.
After you've changed the display properties, you can re-enable the Startup
items.  Windows doesn't need a Config.sys or Autoexec.bat file so unless you
are running some program that requires one or both of these, you can leave
them unchecked.

PattyL