Windows+7+gadgets+do+not+work+or+do+not+display+correctly

If you like Windows 7 gadgets, how aggravating it can be when they stop working or they display incorrectly, such as with vertical green lines down the middle, or as black squares
 * Windows 7 gadgets do not work or do not display correctly**

This can happen for several reasons, ranging from corrupt/missing system files to a System Restore or UAC issues. You will find two different methods for making the gadgets display correctly again in KB article 2515657.