Follow steps below to check if IIS_IUSRS account is granted with full controls to the IIS Web root folder:
Step 1: Right click C:\Inetpub\wwwroot and select Properties from the popup menu.
Step 2: On the Security tab, select IIS_IUSRS in the Group or user names list box, and then check if Allow is selected for Full control in the Permissions for IIS_IUSRS list box. If not, click the Edit button and follow Step 3 to grant full control.
Step 3: Select IIS_IUSRS in the Group or user names list box, and then select the Allow check box for Full control. Click OK to save the settings.
