Setup was unable add user DOMAIN\SVCUSER to local group DOMAIN\SQLServer2005SQLAgent
MSP Error: 29528
Transforming table Error
Create local SQL Server groups for services and assign the users as you need them.
Remove "group" keys in the registry. You will know which ones as they all have word "group" in the name.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.1\Setup
Then install SP2.
Keys will get re-created.