It seems the sidebar.exe utility is involved in this. If it is running, you should show up in the Task Manager on the Processes tab.
You might try opening the Start menu and typing sidebar in the search box. You should see some options that might help. If you don't see sidebar in Task Manager and none of the options on the start menu work, perhaps hit Winkey+R and type in sidebar.exe to see if you can start it.
Have you done anything you can think of to your system that might have changed those normal settings?
Edit: Also, if you open the Control Panel and go to Programs and Features, open that. Click the Windows features option and there is a Windows Gadget Platform option that might need to be checked.