Installation of Enterprise Console 4.5 fails on a domain controller (or backup domain controller). The error returned explains that there was a SQL installation failure.
Known to apply to the following Sophos product and version
Enterprise Console 4.5Operating System
Microsoft Windows Server 2008 R2
What to do
SQL Server 2008 Express Edition cannot be installed on a domain controller on which the functional level is set to Windows 2000.
Set the functional level of the Domain Controller to Windows 2003 or above for the duration of the SQL installation during the Enterprise Console 4.5 installation process.
For more information on functional levels in Windows Server 2008 R2, please see: