Correct Permissions to Update WordPress installed on IIS

To make WordPress update without the need of using FTP, add the following line to wp-config.php

/** Sets up auto update without FTP */
define('FS_METHOD','direct');


To Correct Permissions to Update WordPress installed on IIS, basically you need to give read/write permission to an "Authenticated users" and change the site Application Pool identity to LocalSystem

In IIS manager

1. Go to Application pools and choose the one used by your WordPress site.
2. Right Click and choose Advanced Settings...
3. Change the Identity to LocalSystem
4. Click OK to save changes.

Then on Sites list,

1. Choose your WordPress site from the sites list
2. Right click on it and click on Edit permissions
3. Go to security tab and click on Edit... (Group or user names)
4. Click on add and type "Authenticated users"
5. Give read/write permission to an "Authenticated users"
6. Click OK to save changes.

Now try to update WordPress and it should work perfect !