To prevetn this problem from happening again, make sure you have the correct monitor INF file loaded for your monitor.
Right-click anywhere on your desktop, select "Properties", then select the "Settings" tab and press the "Advanced" button. Now select the "Monitor" tab. If th monitor name is "Default Display" or "Plu N Play", then you need to load the monitor INF driver file. Typically those can be found at the monitor manufacturer's WEB site.
Once that file is loaded, you willnot be able to select a resolution from the Aces High II drop down list that the monitor cannot run.
What happened here is you selected a resolution your monitor cannot run.