Just uninstall it in the gadget select window, do NOT delete that folder. then to reinstall it:
Instructions for Windows 7
Here are the instructions to restore the default Desktop Gadgets in Windows 7.
Click Start, Control Panel. In the search box, type Restore Gadgets
Click Restore desktop gadgets installed with Windows.
You may still need to delete the cache folder as Junior Crooks and Philly mentioned, just not the gadget folder.