.docx file giving HTTP Error 404 within IIS6 website

Problem:

When you request a file with .docx extension from an application served from IIS 6.0, you receive the following error message “HTTP Error 404 – File or directory not found”, even though the file is there & permissions are correctly set.

Solution:

1. Open the IIS Microsoft Management Console (MMC), right-click computer name, and then click Properties.
2. Click MIME Types.
3. Click New.
4. In the Extension box, type: .docx
5. In the MIME Type box, type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
6. Click Apply
7. Recycle the application pool:
   1. To determine application pool: right click the website > properties > home directory
   2. Then: right click application pool > tasks > Recycle