Dell Studio XPS 16 bluetooth vanished?

Ever since I upgraded to windows 7 on my Dell Studio XPS 16, the bluetooth hasn't worked, and I can't find a new driver?

I bought my laptop before windows 7 came out last year. I upgraded it to windows 7 at Christmas, and everything seemed to work fine, with the exception of maybe one driver which I had to update. I've just noticed though, that the bluetooth capability of my laptop has mysteriously vanished. I can't find it in the hardware manager, and can't find any new drivers or anything, which is a little confusing. Thing is I'm not even sure the name of the hardware installed on my laptop that has the bluetooth capability. Will I have a wireless minicard, ie 5540? The bluetooth was a standard option, and I don't have built in mobile broadband or anything. And ideas?