My company recently issued me a Dell Latitude with built in Bluetooth. I was able to pair my BB with the laptop but the BB Desktop Manager refused to recognize my BB. My search on BB Support took me Doc #. KB04132
(Set up Bluetooth connectivity with BlackBerry Desktop Manager). I had the same issue which has been described at the bottom of the document. Additional Info
If the Enable Bluetooth Support check box and Configure Bluetooth button are not selected on the BlackBerry Device Manager Properties window, your computer may not be using original Windows XP SP2 Bluetooth radio drivers. Verify that you are running the Bluetooth device manager that came with Windows XP SP2 (see instructions above).
I tried toying around and did everything but could not make the Desktop Manager recognize my Pearl even though my Laptop Bluetooth paired with Pearl. I tried searching in Microsoft Support site and it was not all that helpful.
I tried Dell SUpport and it did not take me far. TO cut the story short... I came across this in Dell Community forum Replacing Bluetooth Stack for Windows by Toshiba with Microsoft Bluetooth Stack - Software - Windows XP - Dell Community Forum
The problem was Dell Laptop comes with Toshiba Bluetooth. To pair BB Pearl with Laptop and then with the Desktop Manager, the Bluetooth drivers requires to be tweaked.
I followed the instructions to the last word i.e., uninstalled the Toshiba Bluetooth, changed the registry settings and renamed the drivers. That got my laptop to bring up the Blue Tooth Device Manager in the Control Panel. Then I configured the Device Manager to recognize my BB Pearl (I deleted the pairing made earlier while unistalling the Bluetooth). Then opened my Desktop Manager and this time the Bluetooth settings were not greyed out (that was the original problem and mentioned in the BB Doc #. KB04132 (addl info). I then set up the Desktop Manager and it recongnized my Pearl in no time. Now everything works fine.
It took me some eight hours of search in various forums to get the right solution and I could turn around within half hour.