During the update, you can run into the following exception:

Exception: System.Data.SqlClient.SqlException: Address Windowing Extensions (AWE) is not supported in this edition of SQL Server.
Configuration option 'show advanced options' changed from 0 to 1. Run the RECONFIGURE statement to install.

To solve the issue and be able to install the SP2 to your SharePoint Servers, you will need to disable the AWE option in the SQL server properties. If you like, you can switch it back on after the update.

After the AWE has been disabled, execute the SQL commands.

   1:  exec sp_configure 'show advanced options', 1;

   2:  GO

   3:  RECONFIGURE WITH OVERRIDE;

   4:  GO

   5:  sp_configure 'allow updates', 0;

   6:  GO

   7:  RECONFIGURE WITH OVERRIDE;

   8:  GO

   9:  exec sp_configure 'show advanced options', 0;

  10:  GO

It will change an option, which does not do anything in SQL Server 2005.

“This option is still present in the sp_configure stored procedure, although its functionality is unavailable in Microsoft SQL Server 2005 (the setting has no effect). In SQL Server 2005, direct updates to the system tables are not supported.”

After the change, the SharePoint Configuration Wizard will complete the update.