1) Check  that wireless antennas are connected in the back of your motherboard
2) Update drivers from motherboard manufacturer for Bluetooth 
3) If this doesn't work try a Windows clean install.  Instructions below.

You can reset your computer to a full reset by typing Reset into the search box.
You then have the option of resetting with "Keep all my files" or "Remove Everything"

Make sure you completely back up all of your files as it may wipe your data
You'd want to do this if you have an issue with a software that can't be erased or a corrupt Windows installation
Make sure you have a Windows key

If that doesn't work, you can also try to restart the PC by SHIFT+RESTART then you can reset it via Windows Boot Menu