Symptoms: When you attempt to browse to your Magento installation or Magento directory you receive a 403 Forbidden Error.
Solution: This is a normal web server response when the requesting user does not have the rights to access the content it is trying to access. To resolve this issue check the following information:
1. Check the owner of the folder for /httpdocs/ and all subdirectories for the magento installation. The correct owner should be as follows: username:usergroup
In a Plesk 11.5 hosted environment this would be: yourusername:psaserv
If the user is root (which often happens with command line installation) change the owner of the files in httpdocs or the subfolder with the magento installation using SSH and type: chown -R yourusername:psaserv httpdocs/*