Hi,LewisDearman I am not saying that this could be your problem but when I first got my mobile broadband I too received a message saying that the sim needed to be activated,which In my case I knew not to be true as I had already set It up on my other computer and It was working Perfectly.The problem turned out to be lack of signal,believe It or not but If you treat the dongle like a T.V aerial and put It on the extension lead and move It around to try and get a better signal,usually the higher the better next to a window If you are struggling with a low signal.The moderators are very busy and deal with posts In the order they received them,so I am sure they will not be long till they can help you out.
Richard.