Why is there no Back or Next button during the initial setting of the VAIO computer?

When carrying out the Microsoft registration process, there is no Back or Next button to proceed with the registration.

This is the design of the program and this symptom occurs in the initial setting only.
Please refer to the Setting up Windows User Guide. Clicking Skip may result in the Next and Back buttons to be missing on the next screen.
If this happens, use the Power button to restart the computer. When the computer restarts, proceed with the initial setting (OOBE).