This error results when the VBScript engine is not registered. Since HTCondor's installer depends on the VBScript engine for custom steps, the installer will fail if it cannot find the VBScript engine.

The fix is to register the VMScript engine. With Administrative privilege:

  1. Launch the Command Prompt (\Prog{cmd.exe}) as the Administrator.
  2. At the Command Prompt, change directories to the \File{System32} folder, within the Windows folder.
  3. Issue the command 
      regsvr32 vbscript.dll

If successful, the message 

  DllRegisterServer in vbscript.dll succeeded.
is printed.