Windows 7 has pre-installed desktop gadgets such as Calendar, Clock, CPU Meter, Currency etc. and also you can download more gadgets from online. And you can remove a gadget in Windows 7 using the Uninstall option available as apart of the Context menu.
Click Start menu and select Control Panel from the menu list.
In the Control Panel window, select the Programs link and click the Uninstall a gadget link available as part of Desktop Gadgets section.
The following Desktop Gadgets windows will be displayed. Right click the gadget which needs to be uninstalled. A context menu with Add and Uninstall option will be displayed as shown below.
Click the Uninstall option and again select Uninstall button in the Confirmation dialog as well to remove a Gadget from Windows 7