SQL 2005 Express SP2

I recently had some issues installing SP2 for SQL 2005 Express on one of the servers I manage. The installation appeared to complete without incident, however, at every update check I was told that I still needed to install this critical update again.

I tried several times, expecting that my never-waning persistence would fix the problem, but no luck. I even downloaded the update and installed it manually - still no change. I reviewed the installation logs but found no errors. I verified the file versions and everything appeared to be updated. I finally resorted to calling Microsoft's Professional Support Services and with Bob's help, discovered that this was simply a matter of an incorrect registry entry.

The "Version" and "Patch" values under HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\90\Tools\Setup were not updated during the SP2 installation, and were incorrectly set to 9.1.2047 rather than to 9.2.3042.00. Manually updating the values and re-running the Microsoft Update detect cycle resolved the problem.

I can't be sure whether this was the root problem, or just a symptom of something bigger, but so far everything is working as expected. Hopefully this saves someone else a few minutes.