Follow steps below to grant IIS_IUSRS account with full controls to the IIS Web root folder:
Step 1: Right click the C:\Inetpub\wwwroot folder 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 click the Edit button.
Step 3: Select IIS_IUSRS in the Group or user names list box, and then select the Allow check box for the Full control.
Step 4: Click OK to save the settings.
