So I have a CTP of SQL 2005, SQL 2000, and CTP of SQL Express on one of my boxes and wanted to remove it.  Using the add/remove programs (appwiz.cpl) did not display the CTP and would spit out errors when I tried to remove sql 2000… sigh

Therefore, I tried to just install the dev copy of SQL 2005 I got off of my MSDN account, thinking that it would repair or upgrade the installation.  No luck there either… sigh

I turned to some brutal maneuvers at this point.  I turned off all of the SQL services and disabled them (services.msc).  Next I tried to remove the Microsoft SQL directory in program files.  Some of the files were locked, so I ran unlocker on them.  I then deleted the directory, no more SQL as far as I was concerned.

Now I simply had the messy business of removing the registry entries for SQL Server.  To do this I followed the guide located here: http://www.windowsitpro.com/Article/ArticleID/14070/14070.html?Ad=1

Still no luck when I tried to install SQL Server.  At this point I decided to remove the sql entries in the uninstall location of my registry.  This in effect removed my sql 2000 entry from the add remove programs page, and nothing else. 

At this point I decided to turn to the forums at Microsoft, without little success of an answer.  I noticed though that trying to run msiexec /x {2750B389-A2D2-4953-99CA-27C1F2A8E6FD} did show that I still had the CTP installed, but failed to uninstall it.

The final step in my search for SQL removal was to run the Windows Installer Cleanup Utility and remove the CTP from the list.  This can be found here: http://support.microsoft.com/default.aspx?scid=kb;en-us;290301

I hope this is helpful to anyone trying to remove a SQL CTP.  Remember, remove the directories, delete registry entries, and run the installer cleanup.  Nothing could be easier