RICOH THETA is not recognized even when the camera unit and computer are connected with a USB cable.
The camera may have frozen.
Push and hold the power button and wireless button simultaneously (for 6 seconds or longer) on the camera. After the camera has reset, push the power button again.
With a Mac, changing the USB port may solve the problem.
Do you have access to a Windows 10 computer 1709 Fall Creators Update you can try it on as a test? Maybe your friend has another computer? Try different USB cables.