The button for .htaccess will always appear. However, when you click on it you'll see that it warns you that you 're possibly not using Apache. This is a special case. There are servers which do not report their type at all, report a misleading type or are not Apache but still support .htaccess files. So the only thing we can do is always display the .htaccess Maker button (unless we positively detect NginX) and show a warning in the .htaccess Maker page.
There are already some tools hidden from you because you're running IIS, like file permissions configuration (they don't apply to Windows). So yeah, we actually do detect that you're running under IIS ;)
Regarding web.config, it lacks consistent support for redirection rules. Even the redirection support added as an optional module since IIS 7.0 isn't anywhere near as powerful as Apache's, making security tightening with web.config very unlikely I'm afraid :(
Regarding redirection it DOES work - as long as you have the redirection module installed on IIS and you are using a web.config file based on Joomla!'s web.config.txt which enables the URL rewriting features. In any other case IIS doesn't forward non-existing URLs to Joomla!, therefore our code never has the chance to run and act on them. Bummer.
There are no other features which may not work on IIS. Everything else runs at the Joomla! system plugin level and does not rely on specific server features.
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!