anchor.diff:  
   :install_vbox_guest_additions_from_iso
   call :install_sevenzip
  -if errorlevel 1 goto exit1
  +if errorlevel 1 (
  +  echo ==^> ERROR: Failure trying to install 7-zip archiver
  +  goto exit1
  +)
   
   echo ==^> Extracting the VirtualBox Guest Additions installer
   7z x -o"%VBOX_ISO_DIR%" "%VBOX_ISO_PATH%" "%VBOX_SETUP_EXE%" cert
  
positive.code: :: to the correct place.
  set _VMWARE_TOOLS_SIZE=0
  if defined VMWARE_TOOLS_ISO_PATH for %%i in (%VMWARE_TOOLS_ISO_PATH%) do set _VMWARE_TOOLS_SIZE=%%~zi
  if not "%_VMWARE_TOOLS_SIZE%" == "0" set VMWARE_TOOLS_ISO_URL=
  if not defined VMWARE_TOOLS_ISO_URL goto install_vmware_tools_from_iso
  
  echo ==^> Installing the VMware tools using directory %VMWARE_TOOLS_DIR%
  
  call "%SystemRoot%\_download.cmd" "%VMWARE_TOOLS_ISO_URL%" "%VMWARE_TOOLS_ISO_PATH%"
  if errorlevel 1 (
  
negative.code: :: can extract the iso we just downloaded and run its setup.
  :install_vmware_tools_from_iso
  call :install_sevenzip
  if errorlevel 1 (
    echo ==^> ERROR: Failure trying to install 7-zip archiver
    goto exit1
  )
  
  :: Now that we have the iso, we can extract it with 7-zip and make sure its got
  :: everything that we're looking for.
  