Select the Tools menu from the menu bar. From there, select Internet Options.
Select the Connections tab, choose an ISP from the list and then select Settings
Check Use automatic configuration script and type the following address into the
box labelled Address
http://www.aston.ac.uk/proxies/internal.pac
Alternatively, if you also want to access Aston pages which are restricted to aston.ac.uk, use
http://www.aston.ac.uk/proxies/external.withaston.pac
When you have finished, if you no longer want your Internet connection to go via Aston’s proxy, you should un-tick the box next to Use automatic configuration script.