I kept getting a Windows Update notice that SQL Server Express SP3 was ready for installation. Every time I ran the install process, it would fail. There are a lot of posts out there regarding this issue, but I did manage to find one that worked for me, and wanted to share it.

Other failed installations or problems with programs that you are unable to uninstall can be fixed by using Microsoft's Installer Cleanup Utility. This will purge the entries and files for programs that you can not uninstall automatically because some files are missing or corrupt. An installation that does not fully complete can create such issues as well. Just make sure that you are careful in selecting what to clean up because the changes are irreversible without using System Restore or the like!

I have posted a solution that includes this info and that worked for me on the TechArena website here. But consider yourself forewarned: My solution involved cleaning up only the SQL Server Express Installer files, NOT the actual installation itself (MSSMLBIZ).

I hope that this helps someone else.