You are mistaking restore for recovery. I mean taking system back to the factory default Windows operating system. Are you saying the Surface Pro 4 comes with the issues initially when it was bought? He should at least look for a way to forestall them by trying to do the system recovery first because the issue is no longer pertinent to sound.
My TC1000/TC1100 from 2003/2004 (7 years before the crappy iPad) have something to say about that sentence. My ex Nokia 770,N800 and N810 had something to say as well
According to this logic Windows = Linux because both are revolving around a CPU, some ram and some storage.
i had a similar issue with a usb device on anniversary.. what fixed it was windows repair portable in safemode then after reboot remove all sound devices and video display, first remove all software for sound and video and reboot. then device manager right click update driver.. and cliick view> show hidden devices and check for any strange leftovers.
do you have the realtek card set as default,right click sound on taskbar/playback devices/right click realtek set as default ?