I tried to recreate this problem and this is what I found.
I started out with the installation of AdminStudio and once the installation of AdminStudio was done, setup.exe launched the installation of InstallShield Developer.
If I cancel out from the installation of InstallShield Developer and then try to run tuner from AdminStudio IDE, I get the error message "Class not registered". The problem is that InstallShield Developer installs and register some files that are required by Tuner to function properly.
If you install AdminStudio and then let Developer be installed you will not see this error message and Tuner will launch correctly.
Please let me know if you have any other questions.