WP has global $is_iis7 variable, which is filled via following code: $is_iis7 = $is_IIS && intval( substr( $_SERVER[‘SERVER_SOFTWARE’], strpos( $_SERVER[‘SERVER_SOFTWARE’], ‘Microsoft-IIS/’ ) + 14 ) ) >= 7; If detection is not working correctly likely something is going wrong with this line, such as server vars not being filled with the info expected.
Multisite subdirectory root not accessible
Permalinks setting raises 500.0 error
On your current website add Duplicator(a free plugin) and create a new package, that you can use in the new environment. It will give you several options on Storage, Archiving and Installer script.
You can prevent a “hard” flush, which updates .htaccess (Apache) or web.config (IIS), with the flush_rewrite_rules_hard filter. We can also use the __return_false helper function here. add_filter( ‘flush_rewrite_rules_hard’, ‘__return_false’ ); This code can be placed in your own plugin or a theme’s functions.php file.
There was something installed on the IIS server that was capable to read the .htaccess files; and was ignoring the web.config so the WP documentation with .htaccess works for me.
WordPress on shared server Plugin not working
404 Errors on Every Page (Including Homepage) After Migrating From IIS to Apache
WordPress login loop on proxy setup with SSL – Apache proxy to IIS
Configure redirects with web.config