I recently ran into a problem when trying to install SQL Server 2008. Near the end of the install, it does some dependency checking, and my particular install was throwing this error:
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.
I found a few useful blog posts on the topic:
I verified that I did, indeed, have Visual Studio 2008 SP1 installed, and it appeared that I did. I then checked to see if I had any versions of Visual Studio Express installed on the machine, and I did not. At this point I was not quite sure what to do, so I decided to try to find the SQL Server 2008 install log.
The install logs are put here by default:
C:\Program Files\Microsoft SQL Server\100\Setup Bootstrap\Log\
If you then check the folder with the appropriate timestamp (e.g. \20091016_132538\), you’ll see various log files. If you open up Detail.txt and search for “visual studio”, you’ll find the places where the installer is checking the registry settings for the Visual Studio SP version.
In my case, I had installed Visual Studio Developer Edition, and a few plugins, then upgraded to SP1. After that, I had installed the Visual Studio Database Edition addons. It turns out that my instance of Database Edition was still at the pre-SP1 version, which was causing the SQL Server 2008 install to fail.