Installing SQL 2005 Service Packs

Now hopefully no one out there will need this post–especially because SQL Server discontinued support in 2011; however, because I learn something new everyday I feel compelled to put his post up. I came across a server that had automatic updates on and was trying to install SP2 for SQL Server 2005. It would error out and SQL Server would be shutdown. I was trying to install the update for SQL Server and the Analysis Server services.  The error in the log was
Product: Microsoft SQL Server 2005 -- Error 29528. The setup has encountered an unexpected error while Setting Internal Properties. The error is: Fatal error during installation.
When I tried installing the service pack manually, this error displayed in the GUI.
Service Pack 4 for SQL Server Database Services 2005 ENU (KB2463332)'
could not be installed. Error code 1603.

The resolution was to delete some registry keys, which is still gives me the Hebe-geebees, and these were the keys.

SQL Server Entries

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.1\Setup\SQLGroup
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.1\Setup\AGTGroup
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.1\Setup\FTSGroup

Analysis Services Entry

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.2\Setup\ASGroup

After I did this the installation went as expected. Now I just have to upgrade these bad boys.