If you use a proxy server to access the Internet, you can set these parameters in the License Manager to allow you Activate. This process is identical to "Automatic Activation via the Internet," except that you must first enter your proxy server settings as described below.
To do this, click on the ‘Help’ menu on the toolbar and choose “Advanced” from the drop down menu (as below).

You will then need to enter your proxy server settings into the Dialog boxes provided. Click the “Use a proxy server..” check box and then complete the details in the two fields from your proxy server settings. You may need to contact your IT Dept. for these.

Then, continue with the Activation as you would in "Automatic Activation via the Internet."