How can I detect and solve HTTP 404 error?

The HTTP 404 or Not Found error message is a standard response code of HTTP indicates that the client is able to communicate with the server but the server can not find what is requested.

Cause:

By default, when IIS is installed on any version of the Windows Server 2003 family then IIS only serves static content (HTML).

Symptoms:

When you request dynamic content like an ASP.NET page, an Active Server Pages (ASP) page, a Common Gateway Interface (CGI) application or an Internet Services API (ISAPI) application on a Microsoft Windows Server 2003 server that is running Internet Information Services (IIS) 6.0 then you may receive any of the following error messages:

Error message 1

HTTP Error 404 – File Not Found

Error message 2

HTTP Error 404- File or Directory not found

Resolution:

Enable a Pre-existing Web Service Extension in IIS 6.0

To serve content to permit IIS that requires a specific ISAPI or CGI extension (already listed in the Web service extensions list) then follows these steps –

1)    Open IIS Manager, expand the master server node and then select the Web service extensions node
2)    Right-click the extension in the right pane of IIS Manager that you want to enable
3)    Click to select the Allow check box.

Add a New Web Service Extension to IIS 6.0

To permit IIS to serve content that requires a specific ISAPI or CGI extension (not already listed in the Web service extensions list) then follows these steps –

1)    Open IIS Manager, expand the master server node and then select the Web service extensions node
2)    Click Add a new Web service extension under Tasks in the right pane of the IIS Manager
3)    Type a friendly name in the Extension name box for the extension that you want to add Click Add in the required files box and then select the path and the name of the file that will handle requests for the specific extension. When you select the path and the file name then click OK
4)    Click to select the Set extension status to allowed check box if the extension must be enabled immediately
5)    Click OK to save your changes

So, HTTP 404 error indicates that the requested resource may be available in the future.