The group policy can block access to reset Internet Explorer which seems to need it much more than it should. To bypass this and reset the settings back to the default:

From a command prompt:

C:\> RunDll32.exe InetCpl.cpl,ResetIEtoDefaults

This will pop up the Reset Internet Explorer Settings window. Click Reset to reset everything except you personal settings. Obviously, you can check the “Delete personal settings” box if you want to delete you personal settings as well.