To add a site to Trusted Zone-Open Internet Explorer
-Navigate to the website that you want to add to a specific security zone.
-Click the Tools button, and then click Internet Options.
-Click the Security tab, and then click Trusted sites
-The website should be shown in the Add this website to the zone field. Click Add.
-If the site is not a secure site (HTTPS), clear the Require server verification (https:) for all sites in this zone check box.
-Click Close, and then click OK
Sometimes you might come across an error : Can not add a site to "Trusted sites zone"
To solve this error try below method
-Open Internet Explorer.
-Click Tools, and then click Internet Options.
-Click the Advanced tab.
-Under Reset Internet Explorer Settings, click Reset.