A training machine has default instance of SQL 2005 standard with SP2 on it. After installing a new named instance on it, I tried to apply Service Pack 3 to both the default instance and the named instance. SP3 was successfully applied to the named instance, but failed on the default instance with following error: “Product: Microsoft SQL Server 2005 - Update ‘Service Pack 3 for SQL Server Database Services 2005 ENU (KB955706)’ could not be installed. Error code 1603.”
I did some search and found this solution http://www.sqlnewsgroups.net/group/microsoft.public.sqlserver.server/topic23830.aspx.
Following are excerpted from the link:
1. Remove the following registry subkeys that store SID settings:
_HKEY_LOCAL_MACHINESOFTWAREMicrosoftMicrosoft SQL ServerMSSQL.XSetupSQLGroup
HKEY_LOCAL_MACHINESOFTWAREMicrosoftMicrosoft SQL ServerMSSQL.XSetupAGTGroup
HKEY_LOCAL_MACHINESOFTWAREMicrosoftMicrosoft SQL ServerMSSQL.XSetupFTSGroup
HKEY_LOCALMACHINESOFTWAREMicrosoftMicrosoft SQL ServerMSSQL.XSetupASGroup
Note In these registry subkeys, MSSQL.X is a placeholder for the corresponding value on a specific system. You can determine MSSQL.X on a specific system by examining the value of the MSSQLSERVER registry entry under the following registry subkey:
_HKEY_LOCALMACHINESOFTWAREMicrosoftMicrosoft SQL ServerInstance NamesSQL
2. Reinstall the SQL Server 2005 service pack or the SQL Server 2005 hotfix package.