my asus k55vm sx086d laptop bluetooth adapter stops working after installing windows

8.. please help to start? i recently bought asus k55vm sx086d laptop.. its Bluetooth was working correctly but recently when i installed windows 8...it stopped working correctly... i downloaded latest drivers also from the website but still it dint work...it starts when i open system but automatically the adapter closes in 5 minutes... please help me... currently i am using windows 7 and same problem is persisting....