Xbap plugin for firefox in Windows 7


  • Our company has developed an xbap as part of our core web application
    Our application needs to support ie and firefox and at the time we started developing the xbap this was fine because when you installed .net, it pushed the plugin into firefox.
    Now however with windows 7 coming with .net already installed there appears to be no way to install the plugin, I cant find an installer for it and it hasnt been registered with mozilla (Even though the .Net framework assistant has
    I have discovered that i can copy the plugin dll from a different computer into firefox's plugins directory but this is hardly a viable commercial fix

    Does anyone know what the deal is here?
    Tuesday, March 9, 2010 10:52 PM

All replies

  • I've been hoping someone would answer this one. I have the same questions.

    Sunday, March 14, 2010 6:03 AM
  • Hi Kris,

    The WPF plug-in for FireFox is installed along with .NET Framework 3.5 SP1. My suggestion is that you firstly check if WPF plug-in has been installed on Windows 7 using the method mentioned in the below KB article:

    If the WPF plug-in isn't installed on the machine, please re-install .NET Framework 3.5 SP1. You can find .NET Framework 3.5 SP1 from the following link:

    Hope this helps.

    Linda Liu
    Please remember to mark the replies as answers if they help and unmark them if they provide no help.
    Welcome to the All-In-One Code Framework! If you have any feedback, please tell us.
    • Marked as answer by Linda Liu Wednesday, March 17, 2010 3:14 AM
    • Unmarked as answer by Kris Mackintosh Thursday, April 28, 2011 2:29 AM
    Tuesday, March 16, 2010 7:17 AM
  • Is there a plan to release a stand alone installer, it seems a bit overkill to make someone running win 7 reinstall 3.5 sp1 just to get a firefox plugin?
    Wednesday, March 17, 2010 4:15 AM
  • Hello, guys.

    I have the same problem.

    Is there any new solution?

    By the way, Kris , what dll's i need to copy to firefox plugin directory ?

    Monday, July 26, 2010 6:28 AM
  • Unfortunately, the release of the XBAP Firefox plug-in for Windows 7 has been continuously delayed, for inexplicable process reasons. Hang in there.

    An interim solution just for testing is to transplant the plug-in from a .NET Framework installation on Windows XP or Vista. Version 4 is better (even for running v3.5 applications), but it requires another DLL or two from .NET 4, so go for it only if you have .NET 4 installed on Windows 7. The source location is:

    • c:\Windows\Microsoft.NET\Framework\v3.5\WPF\NPWPF.dll - for v3.5 [SP1]
    • c:\Windows\Microsoft.NET\Framework\WPF\NPWPF.dll - for v4

    The easiest way to transplant it is to copy the DLL to c:\Program Files\Mozilla Firefox\plugins\. Or, if you want to keep the normal location, put the DLL there and run regsvr32.exe on it.



    This posting is provided "AS IS" with no warranties, and confers no rights.
    Sunday, August 15, 2010 4:33 AM
  • Does anyone know the license implications of writing an installer that would take care of option listed by Chango, if that is how we wanted to deploy our applications to our customers?  Just wondering if Microsoft allows us to redistribute the dll's or not?




    Thursday, August 26, 2010 2:56 AM
  • Is there any update on the firefox plugin, we are about to release our product and telling clients they have to copy a dll from another computer is hardly an option

    my faith in xbaps has been siverly shaken and we already have plans to replace our xbap for our because of this specific issue


    I dont mean to appear angry at you and I do appreciate the suggestions you have made, im just frustrated :(

    Thursday, April 28, 2011 2:33 AM
  • As stated in the question, this is in regards to windows 7 that already has .net 3.5 installed
    Thursday, April 28, 2011 2:36 AM
  • Hi Chango ,

    I tried accessing the XBAP application using FireFox by placing NPWPF.dll at the Plugins path suggested by you on Windows 7 having .NET 4.0. But I was not able to access the application. The same application is working perfectly fine on IE8 and IE9. Can you please give some more details?

    Thanks in advance.



    Thursday, August 18, 2011 5:32 PM
  • I have .NET 4 installed on Windows 7, but I don't see NPWPF.dll anywhere
    Wednesday, September 26, 2012 6:14 AM
  • I DO NOT think there is a way to reinstall .NET Framework 3.5 SP1 even "Turn Windows features on or off".  The end result is getting some errors during reinstall.
    Wednesday, September 26, 2012 6:17 AM
  • I don't think there is a way until Microsoft to release the xbap plugin.    The other day I studied WPF and was so exciting about writing xbap app.  It is now a disappointment when I am not able to get a sample working in Firefox.   Xbap is pretty much not worth for developer time.

    Wednesday, September 26, 2012 6:29 AM
  • XBAP is not worth persuing. We abandonned our XBAP solution and went with Silverlight. It works much better, is fully supported, and we have been able to do what we wanted without all the problems inherant with XBAP.

    It was sort of cool that Microsoft could actually make XBAP work, but Silverlight is a much better way to go.


    Wednesday, September 26, 2012 12:49 PM