Runtime error 339 typically occurs when the MCI32.OCX (or any of the related .OCX file)file or one of its dependent components
is not properly registered. This type of error will give you a message that reads: “a file is missing or invalid.” By default, Vista is only shipped with the VB 6.0. files required to make it compatible with earlier versions of Windows and Office applications. For this reason, users who upgrade from XP to Vista may get runtime errors when trying to run applications that use MCI32.OCX files for the simple fact that they are not included on the Vista operating system.
The best way to fix runtime error 339 is to uninstall and reinstall the application that is prompting the MCI32.OCX errors. A registry cleaner may be required to make sure that no entries are left in the registry as a result of the un-installation. You may need to shutdown your OS and reboot too.
If the error still occurs, you can download the latest version of the MCI32.OCX file online, copy it to the system folder and run the “regsvr32.exe C:\windows\system32\MCI32.OCX” command to register it.