Get Bluetooth to work with the Microsoft Bluetooth stack.
This small freeware utility will try to install generic Microsoft driver for your bluetooth adapter. The program is based on a widely known method of patching %WinDir%\inf\bth.inf file. It works for most (but not all) bluetooth adapters, both USB dongles and built-in. (See the list of bluetooth devices and hardware IDs known to work. Note that this list is not exhaustive.)
Before making changes to your system the program automatically creates a restore point. If anything goes wrong you can use Windows System Restore feature to revert all changes made to your computer.