Sophos Anti-Virus for Windows 2000+: error 25020 when updating to version 7 and 6.5.7

When upgrading to Sophos Anti-Virus for Windows 2000+, version 7 and version 6.5.7, the following error is reported:

Warning 25020. Sophos AutoUpdate cannot be installed. Some registry keys do not have the correct permissions. Contact your support personnel.

What to do

Please read the warning about editing the registry.
Check the permissions on following registry entries, and ensure that each specifies 'Administrators' with 'Full Control'.
- HKLM\SOFTWARE
- HKLM\SOFTWARE\Classes
- HKLM\SOFTWARE\Classes\interface
- HKLM\SOFTWARE\Classes\typelib
If any of these keys do not have this permission set, then Apply new permissions to the registry entry.
Close the registry editor.

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