Win8 under IIS 8.5 set 404 error page _win server

IIS version: IIS 8.5
Problem description

Build a test site, a total of 2 pages (index.php and 404.php), the default home page is: index.php

When accessing index.php and 404.php, the IIS server responds properly, stating that there is no problem configuring the PHP environment in IIS 8.5.
Visit index.php

Access 404.php

In addition, my error page configuration results are as follows:

Normally, when you visit a nonexistent page (such as: 127.0.0.1/aaa.php), the IIS server discovers that the aaa.php file does not exist, so you should request a 404.php

namely: 127.0.0.1/aaa.php--->127.0.0.1/404.php

However, when I visited 127.0.0.1/aaa.php, I reported the following error:

Solutions

Double-click the error page setting--> the option to select the Status code 404--> Select "Edit feature Settings" in the action Bar on the right--> check "custom error page"

As shown in the following illustration: