After installing IE9 in Windows Server 2008 or Windows Server 2008 R2, Internet Explorer 9 does not support HTML5 video and audio playback, which making less than desire web browsing experience when using IE9 to browse the Internet.

The cause of the non-support of HTML5 video and audio playback is that Desktop Experience feature in Windows Server 2008 or Windows Server 2008 R2 has not been enabled and turned on prior to installing prerequisites of Internet Explorer 9.

The prerequisites that require Desktop Experience to be enabled in order to enjoy full features of IE9 is KB2117917 for Windows Server 2008, which provides fixes and improvements to graphics, media foundation and print functionality in Windows Vista Service Pack 2 (SP2) and in Windows Server 2008 Service Pack 2 (SP2); and KB2454826, which provides new functionality and performance improvement for the graphics platform, and KB2483177, which adds the H.264 and AAC decoders.

Thus, in order to fix the issue, just install the Desktop Experience and then re-install the prerequisite(s) again.

Installing the Desktop Experience feature using the Initial Configuration Tasks Wizard

  1. In the Customize This Server section, click Add features.
  2. Select the Desktop Experience check box, and then click Next.
  3. Complete the wizard by clicking Install.

Installing the Desktop Experience feature using the Server Manager

  1. Open Server Manager: click Start, point to Administrative Tools, and click Server Manager.

    Tip: You can also open Server Manager by typing the servermanager.msc at a command prompt.

  2. In the Features Summary section, click Add features.
  3. Select the Desktop Experience check box, and then click Next.
  4. Complete the wizard by clicking Install.

Then, for Windows Server 2008, download and install KB2117917, while for Windows Server 2008 R2, download and install KB2454826 and KB2483177.

The IE9 should be able to play the HTML5 video and audio now. Else, just reinstall IE9.