Win8 system Fn+F8 (NumLock) can not switch keypad

Installed win8 system, the use of the large keyboard has been configured, and did not find the keyboard can not be used. Later, there was no big keyboard. When typing with the keypad, I found that the letter key pressed by the right hand could not be output. It was the number key and character key marked on the keyboard button. So I used the same operation as the win7 system, and pressed Fn+F8, but it didn't respond.
Workaround: Press “windows key” + “R” to bring up the running window, enter “OSK”, open “screen keyboard”

press“Fn+NumLock”, As shown in FIG. The status is Fn pressed and NumLock is pressed.
The problem that has been entangled for a long time has been solved.