If you are not seeing a network icon on the bottom gray line, then there may be something corrupted in your uTorrent.
Try a clean install. Note your port number (I assume you used it for the router), exit uTorrent and move the Application Data folder of uTorrent to another location. Then re-download uTorrent here:
http://www.utorrent.com/downloads
After install, set the port number to the previous one that you set an exception for in your router.
Also, check your Windows Security center at Start>Control Panel>Security Center to confirm that Windows firewall is your firewall and to check if there is any anti-virus active.