Introduction
I installed the CTP of Microsoft SQL Server 2005 that came with my MSDN subscription months ago. I did this foolishly on my primary workstation without doing it in a Virtual Server or PC environment. I never used it and uninstalled it a few weeks later.
Today, after finally taking the leap and deciding to move forward and start using Visual Studio 2005 and SQL Server 2005, I attempted to install these on the same workstation. The SQL Server installation failed and complained about the Beta version still being installed. The only help that I got from the installation media readme told me to use Add/Remove Programs to uninstall any previous versions; that was a wash since Add/Remove Programs showed none. I jumped to Google and Yahoo! for the answers, and found a lot of articles about SQL Server 2005 CTP and the installation of it, but nothing pertaining to my problem. To make a long story short, I spent about two hours trying to find the answer to the problem from outside sources when the answer was all-the-while housed on my hard drive.
I did not retain any of this information, so the details are "fuzzy", but after going through this ordeal, I talked to a few friends who had reformatted their hard drives because of this issue. This is completely unnecessary and I hope to help people avoid this in future. The setup generates some log files when it fails (which I've already deleted, so some of the exact details are lost to me). For me, these files were in C:\Program Files\Microsoft SQL Server\90\SetupBootstrap\Files I believe. Inside of one of these files, which was very short and nothing to be intimidated by, there was a clear indication as to why the installation failed. It was searching the registry and found some entries that told it the CTP release was still installed. It gave me the handy ID of the culprit in the log file (for me {2AFFFDD7-ED85-4A90-8C52-5DA9EBDC9B8F}) along with some other information that could be used instead. I simply sparked up regedit, searched for {2AFFFDD7-ED85-4A90-8C52-5DA9EBDC9B8F}, and deleted anything that I saw.
Now, before anyone goes out deleting registry entries, it takes some caution and you might want to backup any keys before you delete them. Some of the entries that I deleted were Keys and some were Values. It was dependant on my interpretation of what to delete, but if your alternative is reformatting your computer, you might want to try this first.
