Sounds like you either have some drivers or firmware issue. Try to perform a manual firmware upgrade of the Bluetooth device. Run the following program: C:\dell\drivers\R226750\R226750\Win64\svcpack\SetupBluetoothDFU.exe. The program will prompt you for a ".dfu" file which is located in the same folder C:\dell\drivers\R226750\R226750\Win64\svcpack. After updating the firmware your Bluetooth should be working again. Of course you can also get the rivers on the [http://www.dell.com/support/drivers/us/en/19/Product/latitude-e6400|Dell site]. hope this helps, good luck.