Remove Lock Workstation

HKKU
    \SOFTWARE
     \Microsoft
      \Windows
       \CurrentVersion
        \Policies
         \System

            DisableLockWorkstation (REG_DWORD) = 1

NoBrowserClose

HKCU
    \SOFTWARE
     \Policies
      \Microsoft
       \Internet Explorer
        \Restrictions

            NoBrowserClose (REG_DWORD) = 1 

  http://www.liutilities.com/products/registrybooster/tweaklibrary/tweaks/10159/