function UnregisterServer(const Is64Bit: Boolean; const Filename: String; const Reserved: Boolean): Boolean;
Unregisters the DLL/OCX with the specified filename. If Is64Bit is True, the DLL/OCX will be loaded as a 64-bit image and unregistered in a 64-bit process. Returns True if successful, False otherwise.
Parameter Reserved is ignored, but must be specified anyway.