HTTP Error 401.3 when browsing CRM page

If this error happen to show when browsing CRM page:

HTTP Error 401.3 - Unauthorized
You do not have permission to view this directory or page because of the access control list (ACL) configuration or encryption settings for this resource on the Web server.

First navigate to CRM application pool, check the Anonymous setting. Find out what is the identity.
By default is set to IUSR.

Then navigate to CRM folder, make sure you gave the permission to "IUSR" & "IIS_IUSRS" read and write permission. Remember to replace child permission for all items in subfolders.

This steps solved my issues ;)