This post is focused on installing SQL Server 2008 on a Windows 2008 R2 server for those of only need to do a few installs. In other words, this is the quick fix. At the bottom of this post is the solution for how to resolve this issue if you regularly install SQL Server in this configuration. In other words, at the bottom is the enterprise solution. For me, I ran into this issue building a virtual machine for local testing of SharePoint.
I ran into a problem installing SQL Server 2008 (SQL2K8) RTM onto a Windows 2008 R2 server. After some research, the issue is SQL2K8 is not supported on Windows 2008 R2 without SQL2K8 Service Pack 1. We receive this error message when you try the install:
If you continue the install process, you will get through all the setup screens but the installation of any of the services will fail. The issue is the setup files that come with the RTM version of SQL2K8 cannot properly install the services on the R2 version of Windows 2008. Anything I did from this point forward did not resolve the issue. I did some research and found the answer. I started with a clean Windows 2008 R2 image and started my resolution process from there.
So here is the work around solution. Before you even try to install SQL2K8, run the SQL2K8 Service Pack 1 install. As it starts up, it will install the latest group of setup support files.
After this part is done, it will not detect any installed SQL components (to be expected) and you will cancel the installation. Now run the installation of SQL2K8 just like you always would. The installation will detect that there are newer versions of the setup files installed already and will use them instead. These SP1 setup files are aware of Windows 2008 R2 and your installation will complete successfully.
Remember to go back and re-run the SQL2K8 Service Pack 1 to actually update the installed services on your system now. That is it! You are done!
Enterprise Solution: If you are regularly installing SQL2K8, this solution is very much a work around and adds extra steps and time. The solution for when doing several installs is to make a SQL Server 2008 SP1 slipstream install location. With this solution, you will be able to run the install once, have it install without errors, have the server configured and have the service pack already installed.