This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox 4 won 't play embedded .wmv, have newest plugin

  • 4 replies
  • 202 have this problem
  • 3 views
  • Last reply by AltS7

more options

URL: http://www.richardleighton.biz/demo_reel--comedic.html The embedded .wmv file won't play on Firefox 4, even with the latest plugin for Windows Media files...mostly designed for WinXP and not Win 7. Page plays just fine on Internet Explorer and even Netscape, but not on Firefox 4. Played ok on previous Firefox versions.

URL: http://www.richardleighton.biz/demo_reel--comedic.html The embedded .wmv file won't play on Firefox 4, even with the latest plugin for Windows Media files...mostly designed for WinXP and not Win 7. Page plays just fine on Internet Explorer and even Netscape, but not on Firefox 4. Played ok on previous Firefox versions.

All Replies (4)

more options

I had this problem too. I eventually traced it to an incompatibility with the Realplayer 14.0.2 extension. When I disabled the Realplayer extnsion WMV files played normally.

I upgraded Realplayer to the latest version, which updated my Realplayer extension to 14.0.3 which resolved the problem and I can now play WMV files normally with Realplayer enabled too.

Best wishes

Mike H

more options

Thanks. I've already downgraded back to Firefox 3.6.17 and everything works fine, but I'll try your solution if I decide to go back to version 4. I wish Mozilla had taken the time to work this out prior to releasing version 4 and leaving us to solve these problems for ourselves.

All the best, RL

more options

I converted the files to .mov extensions and now it works fine. I have not tested this on a pc but will have the results by the end of the week. Will let you know.

more options

For me official wmv plugin works properly on that page. Check in your installation folder subfolder 'plugins' and there NPMSWMP.dll.


I'm using Firefox 4.0.1 on XPSP3\Server 2003 SP2 with WMP11.

Modified by AltS7