Does it look like
this?
If so you don't have any wireless adaptors in it but you should get away with just a basic USB wireless adaptor to be honest.
---------- Post added at 21:27 ---------- Previous post was at 21:24 ----------
Something like this
http://www.ebuyer.com/UK/product/75646
or this if you are ok with opening the case to fit a card
http://www.ebuyer.com/UK/product/50127/rb/23566357929
should work ok with the BT wireless hub or if you are feeling flush you can buy one from BT for a lot more money