Sophos Anti-Virus: Unable to select 'Configure Sophos Anti-Virus'

Issue
Unable to select 'Configure Sophos Anti-Virus'

Sophos product and version
Sophos Anti-Virus for Windows 2000+

Operating system
Windows XP Home SP2

What to do

Note: Due to restrictions in Windows XP Home Edition it is not possible to perform the steps below via the Windows Control Panel

Confirm that you are logged in with Administrator rights. Typically this will allow you to make and save system changes without any prompts for credentials from your system or install software.
Add the user SophosAdministrator to your account:
1. Click Start|Run, type: cmd
2. Press enter,
3. At the prompt, type the following text with spaces as shown, replacing nameofuseraccount with the name of your account:
  net localgroup sophosadministrator nameofuseraccount /add
4. Press enter
5. Restart computer
6. Re-open Sophos Anti-Virus

If you need more information or guidance, then please contact technical support.