you cannot have them both installed side by side. to maintain your ASP sites with iRite, you need to uninstall HTML Editor, then install iRite. to go back to HTMLEditor, uninstall iRite, then install HTMLEditor.
It is possible to simply the process by maintaining multiple configuration folders:
In one configuration, you install iRite, then rename that configuration folder to Configration_iRite.
A new Configuration folder will be created, in this one you install HTML Editor.
When you need to use iRite, rename the configuration folder to configuratiuon_HTMLEditor, the rename Configration_iRite to Configuration and vice versa.