There are several ways to enable IIS ISAPI CGI Restrictions. Enabling this feature can be directly in IIS or using Powershell. This section will explain How can enable IIS ISAPI CGI Restrictions with Powershell. Here below is the script for Powershell.

Import-Module webadministration 

function Is64Bit 
 { 
      [IntPtr]::Size -eq 8 

 }

 function EnableIsapiRestriction($isapiPath){ 

 $isapiConfiguration = get-webconfiguration "/system.webServer/security/isapiCgiRestriction/add[@path='$isapiPath']/@allowed" 

if (!$isapiConfiguration.value){ 

set-webconfiguration "/system.webServer/security/isapiCgiRestriction/add[@path='$isapiPath']/@allowed" -value "True" -PSPath:IIS:\ 

Write-Host "Enabled ISAPI - $isapiPath " -ForegroundColor Green 
 } 
 } 

    function EnableDotNet40Isapi($systemArchitecture){ 

$frameworkPath = "$env:windir\Microsoft.NET\Framework$systemArchitecture\v4.0.30319\aspnet_isapi.dll"

EnableIsapiRestriction $frameworkPath      
 } 

    function Main(){ 

if (Is64Bit){ 

EnableDotNet40Isapi "64" 
} 

EnableDotNet40Isapi 
} 

    Main

Now IIS ISAPI CGI Restrictions have been active. Happy programming!