Error: unable to start the bluetooth stack service

Open Task manager.
Go to Services TAB.
In the long list of services look for BthServ
Right Click on it and Start Service.
If you want this setting to become permanent, then you need to Click on the Small Services Button in the task manager below the listed services.
A new window called services will open up.
Click Extended at the base tab. Look for Bluetooth Support Service.
Right click on it and properties.
Change Startup type to Automatic.
Then Click Start
Apply and ok.