http://kb2.adobe.com/cps/402/kb402865.html
On the Windows 2003 server, open the Internet Information Services Manager.
- Expand the Local Computer Server.
- Right-click the local computer server and select Properties.
- Select the MIME Types tab.
- Click New and enter the following information:
- Associated Extension box: .F4V
- MIME Type box: video/mp4
- Click OK.
- Restart the World Wide Web Publishing service