Adding entry in the Registry

To add an entry in the Registry:

  1. Close the Microsoft Excel, if open.
  2. Launch the Windows Registry Editor (Windows Start button > Search > REGEDIT.EXE ).
  3. Navigate to the subkey - HKEY_CURRENT_USER\Software\Microsoft\Office[OfficeVersionNumber]\Excel\Security.
    Note: The [OfficeVersionNumber] must match with the version number of your installed MS Office. The OfficeVersionNumbers are:
    • Office 2003 - 11.0
    • Office 2007 - 12.0
    • Office 2010 - 14.0
    • Office 2013 - 15.0
  4. Create a new DWORD value :
    • Value name: ExtensionHardening
    • Value type: REG_DWORD
    • Value data: 0
    The value data settings appropriate for the ExtensionHardening setting are:
    • 0 : Do not check the file name extension and the file type, and bypass the function of the warning message.
    • 1: Check the file name extension and the file type. If they do not match, display the warning message
    • 2: Check the file name extension and the file type. If they do not match, do not open the file.
  5. Close the Windows Registry Editor.