Make sure Flash, Silverlight and WMP are working correctly. Try to reset Firefox if you didn't already.

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

If it still doesn't work, try to upgrade your video drivers to their latest version.

I found a page with MS Office demo videos, and I get nothing but the box with a blank white page. I get no audio as well as no video. You do have javascript enabled, right? That is needed. The code is a bit strange. It is not loading a movie clip or anything like that. Here is a piece of it:

<a class="cntArticleMediaLink" href="javascript:OpenPlayer({Player:'mediaplayer',DownloadAssetId:'ES010240320',ThumbnailAssetId:'',Width:884,Height:540,Type:''});">Play Demo&nbsp;<img style="visibility: visible;" src="//officeimg.vo.msecnd.net/en-us/files/947/322/ZA010132940.gif" alt="Demo button" title="Demo button" border="0"> </a>

Apparently using the Windows Media Player is mandatory. What AssedId 'ES010240320' is, I have no idea.

Thanks, but the reset did not fix it. BTW, I can paste that url into IE and it works fine. (Of course also works if I make IE default broswer).

This is a brand new PC so don't see how a driver could be an issue. I had this same problem several years ago on my former PC and it got fixed somehow, but unfortunately I don't remember how/what happened.  :-(

Maybe the website thinks you are under IE and tries to load a ActiveX control, or maybe it's just designed for IE and nothing else. If you want to use Firefox anyway, you can always instal IETab.

I also get audio only. The headers for the video look fine (basically the same between IE8 and Firefox 14):

HTTP/1.1 200 OK
Cache-Control: public, max-age=86400
Content-Length: 7494540
Content-Type: video/x-ms-wmv
Last-Modified: Fri, 16 Oct 2009 02:25:34 GMT
Accept-Ranges: bytes
ETag: "{C4AB34D9-05C7-4155-A11B-BCC231C965D2},2pub"
Server: Microsoft-IIS/7.5
Content-Disposition: inline; filename=ZA010278646.wmv
SPRequestGuid: d6731c3e-284f-444f-9ae1-8277fc16f6db
X-AspNet-Version: 2.0.50727
X-LLCC: en-US
X-Machine: BLUREN117
X-Powered-By: ASP.NET
MicrosoftSharePointTeamServices: 14.0.0.6114
Date: Wed, 22 Aug 2012 20:52:07 GMT

The video is saved in the IE cache folder (Windows Media Player doesn't use Firefox's cache) and if I try to copy it to the desktop and try to play it in WMP, I get a speeded up audio track and no video. ??

I can't tell whether the fault is with Firefox or with the Windows Media Player plugin for Firefox or with the scripts in the page.

However, if I just load the video URL directly -- I've inserted a space to avoid it being picked up by search engines; delete that when you paste to the address bar -- it plays full tab just fine.

http://office.microsoft.com/en-us/ redir/ES010278647.aspx?CTT=11

??

I also get only audio, and I use VLC plug-in for playback.

Are you sure what you downloaded is a video and not a podcast or similar?

The video format is MSS2, so you need to install a codec that can handle that video format.

I managed to play the file correctly with MPlayer on Linux after installing the w32codec-all (Win32 and other binary Codecs) package.
Should be working on Windows as well.

• http://www.mplayerhq.hu/design7/dload.html

Latest all package (all-20110131.tar.bz2)

• http://www.mplayerhq.hu/MPlayer/releases/codecs/all-20110131.tar.bz2

Thanks for all the input!

Installed ietab and that is a great workaround that I should have thought of, but didn't.

cor-el: I am running 64 bit windows. Is that link a codec I can just install and it will work or is that a completely different viewer?

marcsances: It's help within MS office 2007. That is, I click help icon in Access 2007, then office online opens and I click "demos".

MPlayer is a different viewer that comes with its own codecs.

I've been using MPlayer for quite some time, both on Windows in the past (that was on a slow computer and MPlayer was able to play all frames at a slow rate) and on Linux where it is more or less standard and it plays almost anything from Flash FLV and also this MSS2 format.

• http://www.mplayerhq.hu/DOCS/codecs-status.html
• http://www.mplayerhq.hu/MPlayer/releases/codecs/

The SUMO KB recommends this player for Linux (gnome-mplayer uses MPlayer):

• https://support.mozilla.org/en-US/kb/play-windows-media-files-in-firefox#os=linux&browser=fx15

Thanks, but I'm going to take the conservative route and go with ietab as a workaround.