In the image it says it can enter ports 1020-5000, the BL ports are 28000..that could be a problem but I doubt it.
Plus...not to get in your bizz but why would you want to host if you have Dial Up...or at least have Dial Up selected on BL (not a smart option, makes game loading slow).
You can try some of these,
Change the port numbers to only 28000
Try 192.168.15.143 to enter in the "IP Address" or try selecting the drop down list from "Computer Name"
If none of this works then I have no idea what to tell you, Port forwarding is easy as hell. If you are restarting your PC when doing this then that can be the problem, you need to set your IP to static on windows, but only if you are restarting each time.