For Windows:
Minimize all windows. (That means click the little "-" symbol in the upper right hand corner
of any window in your screen.) Then click with the right side of your mouse...
...Select "Properties," from the little menu you'll see and you'll find THIS box:
After you click "Apply," the screen will go blank for a few seconds...(DON'T PANIC!!!)
...and then light up again with the selected settings. You will be asked if this is
OK, and if it is, simply click "yes," and close out the boxes by clicking the little
"x"s in their upper right hand corners. Simple, huh?
For MAC:
In OS X, click on the little green apple in the upper left hand corner of your screen, then on
"System Preferences" You'll find THIS box:
Once you click on "Displays," you'll find THIS box:
...this tutorial will be refined for clarity... we promise...