I'm guessing you're using a BlueSoliel BT adapter becasue you can't see the MicroSoft BT options on the taskbar or in control panel (and you're having some of the same problems I had this week!). Don't worry, I found that the BlueSoliel software works fine. Infact, you hardly need to touch it once it's installed.
The incoming/oucoming port selection screen is found under:
Start>Settings>Bluetooth>Bluetooth>Menu>Com Ports on the C550. You may find that you can't add either an incoming/outgoing port though, can't remember which one it was (more on that later).
I would recommend following the (excellent) guide here, with the follwoing exceptiond for BlueSoliel:
You don't have the MS BT drivers installed, and the BS program won't let you add an incoming port, so when you get to this stage turn BT on (set to discoverable is probably best) on the phone. Click the orange button on BS and it should find the phone I think phone icon appears on BS screen.
Now that it's connected with the PC you should be able to turn the outgoing and incoming ports on (one of them will have been greyed before).
From this point you can pretty much follow the guide.
Hope that helps, and sorry my memory is so sketchy, I've tried so may options and setups this week I'm struggling to remember which ones I used when I finally got it working! But the guide is very good and worked for me, taking into account the differences with MS/BS software and the C500/C550. Good luck!