The main issue with connecting to the Blackberry desktop manager is the installed Bluetooth stack. Desktop Manager was written for the native Microsoft Bluetooth stack and in most cases won't recognize third party Bluetooth drivers. The only way to resolve this is to turn off the Bluetooth radio on the PC and remove (via add-remove programs) any third party Bluetooth drivers. Once the drivers are removed, reboot the computer and turn the Bluetooth device on. Windows will recognize the new hardware and install the native Microsoft Bluetooth drivers.
On your Blackberry Enterprise Server, the IT policy will have to be modified to allow for desktop Bluetooth connectivity. Under the Bluetooth Policy group, set 'Disable Desktop Connectivity' to false.
In BLACKBERRY DESKTOP MANAGER, click options, connection options. Click on the checkbox to 'Turn on Bluetooth support'. Next, click on the configure Bluetooth button, then click 'Add' to search for your blackberry device. Do the usual steps to pair your device to the computer. Once pairing is complete, a new option in the connection dropdown will appear for Bluetooth with your device PIN. Choose this and click 'OK' to accept the new connection. You are now connected via Bluetooth. The only options that will be available in Desktop Manager are 'Backup and Restore' and 'Synchronize'.