I found this error after installing PHP on IIS, and attempting to browse to a local .php page.
Do the following to fix it.
1.) Go to Add / Remove Programs
2.) Click "Turn Windows features on or off"
3.a.) Open "Internet Information Services"
3.b.) Open "World Wide Web Services"
3.c.) Open "Application Development Features"
3.d.) Tick "CGI"
3.e.) Click "OK
3.f) Wait for it to complete.
4.) Attempt to go to your php page again.