Question / Problem:
Why is it not possible to install Kofax Insight into a website with an underscore (_) in its name ifIIS permits it?
Answer / Solution:
This is an application design best practice that is shared by many application vendors.
Many DNS providers do not resolve to websites with an underscore, therefore, many application vendors will not permit it, regardless if the web-server software you are using allows it or not. This is general information available on any search engine. As an example: http://domainkeys.sourceforge.net/underscore.html