no audio device is installed

Just need to know how to fix this for my friend if anyone can help post on this

Without any PC spec's it makes it hard to try and help.

Is this a new install and it never worked? Or has it worked and now does not?

If this is a PC with in-built audio (on the motherboard) is it enabled in the BIOS? Also has the motherboard chipset drivers been installed or reinstalled?

As you see, we can't really do much without more information.

The first thing you can do is make sure that your sound devices didn't become disabled. Right-click on the volumn symbol at the left of the taskbar, click on playback devices. If they all say disabled, enable the one you want, "headphones/speakers" should be the built-in speakers.