Developers Edition detects previous install, disables Server Configuration option

I installed CF 8 on my workstation a while back and then I completely removed CF 8. I was testing the installation before upgrading a server.

Now I am trying to install the CF 8 Developer's Edition on my workstation. I want to install it in "server configuration" mode. However, the installer has disabled both the "server configuration" and "multiserver configuration" options citing that it has detected a previous installation of CF 8.

I've scanned the windows XP registry and there are no references to cold fusion 8. I looked for any old cold fusion files on my hard drive and removed them. I removed any references to cold fusion left over in my environment variables.

What do I need to do to enable CF 8 developers edition to install cleanly in server configuration mode?