IIS: Cannot read configuration file due to insufficient permissions


Normally I don’t work with Windows Servers and/or IIS, but sometimes you don’t have any other option.
I couldn’t access the web files, it was displaying an ‘500 – Internal server error‘ error.
The more detailed error showed me the following:

Cannot read configuration file due to insufficient permissions

After Googling, searching, trying and again Googling I found a solution.
You have to grant read permissions to IIS_IUSRS on the ‘httpdocs‘ directory.