A possible solution from a related thread:
"EricJames2
It took me hours to come across the actual solution to this issue on a youtube video.
Check your device manager and see if there is an unknown USB device showing. If so, this is likely your Bluetooth.
Simply uninstall the "USB 3.0 eXtensible Host Controller" and restart your computer.
After all the b.s. on here and everywhere else, this is what fixed my problem. At least someone knows what they're doing somewhere, the hard part is finding them!
Elaine
I've had the same problem repeatedly off and on with my Dell Alienware R3. It does seem to happen frequently after Windows Updates get installed. I just found a solution on the Killer Networking web site while checking for a newer Blue Tooth driver. It was very informative. Bear in mind that Blue Tooth is just a USB device. If a USB device gets an error it may result in Blue Tooth getting turned off. Here's what to check:
1. Bring up Device Manager (Its on Control Panel OR right click on My Computer and select Manage or type Device Manager in the search box at lower left of screen)
2. Scroll down to the Universal Serial Bus Controllers. Check the USB list to see if one has an Error listed. If so, Uninstall the offending USB entry and Reboot your system.
Other thing to check is to bring up services ( (type Services in the Search box lower left of screen). Make sure that your Blue Tooth Services are running using the Automatic start selection. Sometimes when Blue Tooth is shut off the services get shut off too. They need to be on for it to work.
Elaine"