First of all, make sure that bluetooth is turned on in PC settings>PC and device>Bluetooth. Next, go to desktop and look in the notification tray and look for the bluetooth icon. If it's not there, bluetooth may still be on but the icon may have been accidentally deleted. Go to your start screen and search for something like "Change bluetooth settings". (Mine's in Japanese and I don't know the exact wording.) In that setting, there will be an option to display the bluetooth icon. Check it if it hasn't been already.
If you're saying that all of the above has been done and bluetooth still doesn't show up after a reboot, I'll need more details...