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.
1: At the Command Prompt, change directories to the \File{System32} folder,
within the Windows folder.
1: Issue the command
{code}
  regsvr32 vbscript.dll
{endcode}

If successful, the message
{code}
  DllRegisterServer in vbscript.dll succeeded.
{endcode}
is printed.