While SQL Server 2008 has reached the release (RTM) stage, there’s a potential gotcha that’s going to prevent many of us from upgrading right away.  The issue is that the SQL Server 2008 installer requires you to have installed Service Pack 1 for Visual Studio 2008 in order to complete the setup process.  If you can’t yet meet this requirement, you’ll receive the following error message:

A previous release of Microsoft Visual Studio 2008 is installed on this computer. Upgrade Microsoft Visual Studio 2008 to the SP1 before installing SQL Server 2008.

The issue is described in Microsoft Article 956139: Visual Studio 2008 SP1 may be required for SQL Server 2008 installations.  Unfortunately, the article seems to leave out an important point: The release version of Visual Studio 2008 SP1 is not yet available (you can download and install the Microsoft Visual Studio 2008 Service Pack 1 Beta, but it won’t meet the installation requirement).  So what can you do? 

It looks like we’ll all have to wait until the final release of VS 2008 SP1.  You can also read more about what features are included in the update at the VS 2008 SP Beta site.  Microsoft currently states that it will be available by August 11th, so it shouldn’t be too much longer.  Still, a better-coordinated release process (and bigger warnings) would have been helpful.