85.SOLUTION : Icons in Control Panel are controlled by the .cpl files. TweakUI allows you to hide these icons from the Control Panel. The problem is that it does not prevent you from hiding its own Icon.
However, here's what you can do to fix this problem. Go to Start>Find>Files and Folders. Here, enter *.cpl and click OK. You should get .cpl files. Find TweakUI and right-click it. You should find an option, 'Open With Control Panel', Selecting this option will open TweakUI. Then click on the Control Panel tab and click on the TweakUI checkbox. This should solve the problem.