What is the System Management Controller?
The SMC is a subsystem in Mac computers that helps control power management, battery charging, video switching, sleep and wake mode, LED indicators, keyboard backlighting, and a bunch of other stuff.
When your computer goes in and out of sleep mode, the SMC will control what devices are powered down to save battery. And this is where the problem lies. The SMC gets the wrong signal and thinks the Wi-Fi adapter should stay powered off even when the computer comes back to life.
Resetting the System Management Controller (to Fix Your Wi-Fi Problem)
If you’re using a device that doesn’t have a removable battery, which is pretty much all devices that Apple has made for a very long time, you’ll need to close down your apps and then use a simple key combination.
Newer MacBook without a Removable Battery
- Plug the laptop into a power source
- Press and hold all of these keys at the same time: Control + Shift + Option + Power
- Release the keys
- Press the Power button to turn it back on
This should fix the problem
Original Article: http://www.howtogeek.com/227662/how-to-fix-the-wi-fi-no-hardware-installed-error-on-os-x/