What did you do when you first encountered the problem? A network and sharing center looking like that seems like some kind of bug made either a strange update or an error when installing windows 7.
Is the rest of the control panel intact? What happens if you restart in to safemode, same problem?
Try this command in a command prompt and then restart the computer:
net localgroup "Administrators" "Local Service" /add
I found it in a thread for a vista computer but it may work for you.
EDIT: We maybe should keep on this discussion in your thread instead. Cant' Detect Wireless Networks: Very Different Problem