EDIT: do you see the SAB log in right low corner, possible after clicking on the up-arrow for hidden pictograms? Right-click on it, select Troubleshoot, then "Restart on 127.0.0.1:8080"
OLD
OK, Windows. Do you have MS IE, can you IE to access the page? If so, you can then in the SABnzbd GUI change to port 8080.
If not, stop SABnzbd.exe (via Process Explorer?), open a CMD, go to the directory containing sabnzbd.exe, and start it with "sabnzbd.exe -s 0.0.0.0:8080 -b1", and you should be fine.