SYMPTOMS
When a .asp file encounters an error, the following standard HTTP 500 error message is displayed instead of an error returned by the 500-100.asp file:
The page cannot be displayed
There is a problem with the page you are trying to reach and it cannot be displayed.
...
HTTP 500 - Internal server error
Internet Explorer
CAUSE
The .asp file is located on a non-default Web site that, by default, does not use the 500-100.asp file for error handling.
NOTE: This behavior is described in the Internet Information Services (IIS) product documentation at http://localhost/iishelp/iis/htm/core/iiprstop.htm.
RESOLUTION
To use the 500-100.asp file for error handling on the non-default Web site, Perform the following steps: 1. Start the Internet Service Manager (ISM), which loads the Internet Information Services snap-in for the Microsoft Management Console (MMC).
2. Right-click the appropriate Web site, click New, and then click Virtual Directory.
3. In the Virtual Directory Creation Wizard, click Next. In the Alias text box, type IISHelp, and then click Next.
4. When you are prompted for the path to the content directory, click Browse, select the WINNT\Help\IisHelp folder, and then click Next.
5. On the Access Permissions page, accept all the defaults, click Next, and then click Finish.
6. Right-click the Web site again, and then click Properties.
7. On the Custom Errors tab, select the 500;100 error line, and then click Edit Properties.
8. In the Message Type list box, select URL, and then type /iisHelp/common/500-100.asp in the URL text box.
9. Click OK twice to return to the ISM.