Hi reefisher,
If you have not yet made any important system settings of your own, you can carry out a system reset by holding down the highest white key (C6 on the Tyro5-61, G6 on the Tyros5-76) on the keyboard while switching on. (Do not release the button until the Main Display is shown.)
A System Reset will probably NOT do anything about your USB MIDI Driver problem, it just resets all User System settings to the factory values.
Make sure that in "Function > MIDI" one of the Preset MIDI Templates "All Parts" or "KBD & STYLE" is activated.
Important: If you select a different template there, you must CLOSE the MIDI display by pressing the EXIT button so that the current template is automatically loaded again when you restart.
You mentioned Windows Explorer above. There are no settings that affect the USB-MIDI driver.
The USB Storage Mode (with which the internal T5 hard disk can be displayed in Windows Explorer) also works without an installed USB-MIDI driver. To boot the T5 into USB Storage Mode, press and hold the MUSIC FINDER button while powering on.
As said, you normally do NOT need to call up the graphical user interface (GUI) of the USB-MIDI Driver. The ports are not selected in the driver's GUI, but, as also mentioned, in the MIDI settings of the program used on the computer. In any case, the driver installation can only be completed successfully if the T5 was connected to the PC via a USB cable BEFORE the installation began, and the T5 was properly recognized by the installation program during installation. With which MIDI program would you like to use the T5 via USB-MIDI connection?
If you continue to have problems, please open Windows Device Manager and see which entry appears when the T5 USB cable is plugged into the PC and disappears when the cable is unplugged. Then (with the USB cable connected) right-click on this entry and select "Uninstall". Then run the driver installer again.
I wish you success!
Best regards,
Chris