You upload an Office 2007 file (pptx, xlsx, docx, etc.) to your IIS6 web server and someone tries to download it, but receives:

HTTP Error 404 – File or directory not found.

Internet Information Services (IIS)

The file is on the server. The URL is correct. You can even download ppt, doc, xls, zip, and other files from the same location. What’s up???

Out of the box, IIS6 only accepts requests for known MIME types. Since Office 2007 was released after Windows Server 2003 and IIS6, IIS6 knows nothing about the new MIME types. So you need to manually add them:

  1. Open Computer Management. (Right-click My Computer… Manage…)
  2. Right-click Internet Information Services (IIS) Management… Properties…
  3. Click MIME Types…
  4. Click New… and add the following:
Extension MIME Type
.xlsx application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
.xltx application/vnd.openxmlformats-officedocument.spreadsheetml.template
.potx application/vnd.openxmlformats-officedocument.presentationml.template
.ppsx application/vnd.openxmlformats-officedocument.presentationml.slideshow
.pptx application/vnd.openxmlformats-officedocument.presentationml.presentation
.sldx application/vnd.openxmlformats-officedocument.presentationml.slide
.docx application/vnd.openxmlformats-officedocument.wordprocessingml.document
.dotx application/vnd.openxmlformats-officedocument.wordprocessingml.template
.xlam application/
.xlsb application/

N.B. These MIME types were added to IIS7 as noted in KB936496.