Here's what I did to fix that:
- Click Start >> All Programs
- Click Windows Update
- In the Windows Update window, there's a link that says "Learn More" or "More Info"... click it
- This takes you to a Microsoft Page where you get to make a choice. While the verbage is designed to steer you towards picking their reccommended setting, as I understand it, either choice will upgrade your Windows Update to now include SQL Server.
- Click Install, and you should be brought back to the Windows Update window, where it should already have begun a scan of your local drive.