Troubleshooting SQL Server 2008 Installation on Windows Server 2008 R2
When installing SQL Server 2008 on a Windows Server 2008 R2 system, you may get the following message: "You must use the Role Management Tool to install or configure Microsoft .NET Framework 3.5 SP1". Following that, another error message pops up: "Microsoft .NET 3.5 installation has failed. SQL Server 2008 Setup requires .NET Framework 3.5 to be installed.". The installation then aborts. In this tip we cover how to get past this issue so you can complete the installation.
A few days ago I was installing SQL Server 2008 x64 bit Standard Edition on a newly commissioned database server . The server was installed with Windows Server 2008 R2 x64 bit Standard Edition. The application vendor's documentation had specified SQL 2008 as the preferred DB back-end so I decided not to go ahead with SQL 2008 R2.
The installer had shown me the following warning message at the very beginning:
This was fairly straightforward - I was going to install SP3 as part of post-installation configuration anyway, so I decided to move forward with "Run Program".
Next came the .NET Framework setup part: the following message was shown, which was also expected:
I was then expecting the setup program to finish extracting and installing the required packages, but halfway through the following message-box popped up:
After clicking OK, another message followed:
Clicking OK then quit the installer, leaving me wondering what went wrong. A bit of researching allowed me to understand the reason. The error was caused by the fact that although Windows Server 2008 R2 ships with .NET Framework 3.5, it's not installed/enabled by default. To make things work, it has to be added as a feature.
Just to be sure on my part, I looked for the following registry key:
HKEY_LOCAL_MACHINE\Software\Microsoft\.NET Framework Setup. The version listed under the NDP folder showed a value of 2.0
I then started the Server Manager by going to Start > All Programs > Administrative Tools > Server Manager. Selecting the Features node on the left side navigation pane showed a link on the right side detail pane "Add Features"
As I clicked on it, the following screen appeared:
I knew what features I wanted to have installed. Selecting the check box for ".NET Framework 3.5.1 Features" and clicking on "Install" took me to the following screen:
As I agreed to add the required Role Services, the next few steps were intuitive:
I then decided to check the registry values again. This time, it showed the version 3.5 folder:
I was then able to proceed with the regular installation of SQL Server and the Service Pack installation after that.
- Refer to the Microsoft TechNet article about known issues for SQL Server 2008 installations.
- Learn more about installing, checking versions and upgrading .NET Framework.
- Learn more about using Windows Server Manager and how you can assign roles, add features etc.
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Article Last Updated: 2012-03-14