I have been tossed back n forth from Windows to Casio to see where the fail is. I have been working on this issue for HOURS! I looked in Control Panel/Device Manager and it says that the Casio USB Midi working properly (in Properties) yet in Events shows that the device is not migrated. I plugged in my Casio LK-165, and neither software shows it as an input device.
CASIO CTK 710 MIDI CONTROLLER WINDOWS 10 WINDOWS 10
I have a new (purch 2019) HP Windows 10 Laptop. The majority of these were Windows-7 to Windows-10 upgrades, while others were a manufacturer carry-over of outdated BIOS into early Windows-10 units, so check to see if your computer hardware has the latest BIOS updates. Other Windows-10 systems indicate problems with outdated BIOS on the computer hardware. In either case, you would need to contact Microsoft Support for assistance.
Some early Windows-10 systems were shipped without the USB-MIDI Class Compliant driver, so if your Windows-10 was an early release, this could be the problem. The USB ports on most(?) keyboards are not compatible with USB-3 cables. It's like the USB-2 hub acts as a "buffer" between the USB-3 computer port and the keyboard's USB-2 port (and USB-1 ports on older models). Some owners have reported success with this. If your computer has only USB-3 ports, you can try connecting a USB-2 hub to one of the USB-3 ports, then connecting the CTK-4000 to one of the hub's ports. If your computer has both USB-2 and USB-3 ports, and you are using a USB-3 port, switch to one of the USB-2 ports. Here is a discussion of possible problems, and some of the more popular tips, fixes, and workarounds: While the great majority of Windows-10 systems work fine with USB-MIDI, there are a few exceptions that have no end of problems. Your CTK-4000 IS USB-MIDI Class Compliant, and should work with your Windows-10 system.