After upgrading to Windows 10 many users experienced a sudden death to the wireless switch built-in into the OS. It would not turn on, and it will stay disabled thereby limiting the ability to connect to WiFi, no matter what you do. A couple of users also reported that re-installation of the entire operating system returned nothing fruitful, and the usual built-in troubleshooters also did not help. Therefore, if you’ve already tried all of the above, then what worked for most was to reset BIOS (basic input/output system). Before you attempt to reset BIOS, i highly recommend that you back up any and all of the important data on your PC/System to an external drive. In case something goes wrong (rarely does) your data should not be lost.
How to Reset BIOS to Fix Unresponsive Hardware Components
Procedure for getting into BIOS is different for different manufacturers. Therefore it would be a trial and error approach to get into BIOS. Most manufacturers, show a Function Key (usually F2) at the POST screen, the one that immediately comes up when you first start the system. Pressing this key immediately and whilst on the POST screen, you will be taken to BIOS. To begin, turn off your computer and start it again. Repeatedly, press ESC key (try pressing it even before you turn it on). This will halt the POST screen giving you time to view the keys. Once you’ve noted down the BIOS Key, press it to enter into BIOS.
Once you’ve entered into BIOS, you will need to use the TAB key on the keyboard to browse to the other tabs, and the arrow keys to choose options. Use these two keys, and locate the option to reset BIOS to Factory Defaults, it may say “Factory Defaults or Optimized Defaults”.
Once done, press F10 key or the one that says it will save your settings. Save it, and restart. Once done, test / check to see if the wireless option is now enabled.