Remove Microsoft .Net Framework Assistant From Firefox

Martin Brinkmann
Feb 9, 2009
Updated • Nov 1, 2019
Firefox, Firefox add-ons
|
45

If you take a look at the installed add-ons in Firefox you may notice an add-on called Microsoft .net Framework Assistant.

That add-on is different from most other installed add-ons: the first thing that you will notice is that you cannot uninstall it as the uninstall option is inactive in Firefox. You may also realize that you did not install that add-on actively which means it must have been installed by another application.

The Firefox Extension Guru posted a walk through on how to remove the Microsoft .Net Framework Assistant.

It basically comes down to the following steps (it might be a good idea to backup all data before proceeding).

  • Make sure Firefox is closed.
  • Go to C:\WINDOWS\Microsoft.NET\Framework\v3.5\Windows Presentation Foundation\DotNetAssistantExtension in Windows Explorer and delete everything in that folder but keep the folder name.
  • Start Firefox. The add-on should not be in the list anymore.
  • Type about:config in the Firefox address bar.
  • Filter for the entry general.useragent.extra.microsoftdotnet
  • Right-click that entry and select Reset

The process is apparently a bit more complicated for Firefox 3.1 beta versions as the Microsoft .Net Framework Assistant is not yet compatible with that version of Firefox and thus not completely installed.

Update: The extension is automatically installed when Windows is updated either manually or directly using Windows Update.

The main purpose of the add-on is to support .NET application deployment. The .Net Framework Assistant for Firefox which is included with the .Net Framework 3.5 Service Pack 1.

It enables stand-alone "ClickOnce" applications to run from the Firefox browser.

Microsoft has published a support page that details how the .Net Framework Assistant can be removed from the Firefox web browser.

  1. Install the update to .Net Framework 3.5 SP1 which installs the add-on on a per-user basis which enables the uninstall button in the Firefox Add-on Manager.
  2. Remove the add-on by deleting the {20a82645-c095-46ed-80e3-08825760534b} subkey in the Windows Registry. You find it for 32-bit systems in HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Firefox\Extensions and for 64-bit systems in HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mozilla\Firefox\Extensions.
Advertisement

Tutorials & Tips


Previous Post: «
Next Post: «

Comments

  1. anon said on April 30, 2012 at 10:35 pm
    Reply

    Make yourself this BAT file and run it – solves everything and NO REINSTALS from Windows Update!
    Copy text bellow and put in somethingsomething.bat made with notepad:

    rem For x86-based computers:
    reg DELETE “HKLM\SOFTWARE\Mozilla\Firefox\Extensions” /v “{20a82645-c095-46ed-80e3-08825760534b}” /f

    rem For x64-based computers:
    reg DELETE “HKLM\SOFTWARE\Wow6432Node\Mozilla\Firefox\Extensions” /v “{20a82645-c095-46ed-80e3-08825760534b}” /f

    rem Addon will want to reinstall itself :( if deleted completly
    rem so delete and then create empty dummy file
    rd /s /q “%Windir%\Microsoft.NET\Framework\v3.5\Windows Presentation Foundation\DotNetAssistantExtension\”

    rem recreate dir
    md “%Windir%\Microsoft.NET\Framework\v3.5\Windows Presentation Foundation\DotNetAssistantExtension\”

    rem make empty file for Windows Update checks
    rem.>”%Windir%\Microsoft.NET\Framework\v3.5\Windows Presentation Foundation\DotNetAssistantExtension\MicrosoftDotNetFrameworkAssistant.xpi”

    1. anon said on April 30, 2012 at 10:38 pm
      Reply

      Repleace ” ” with proper double quotation sign: ” from keyboard
      In the above comment it got replaeced with wrong quotation marks…

  2. RD said on October 27, 2011 at 5:16 pm
    Reply

    Bookmarked.

    Thanks Martin.

  3. Chrissie said on May 8, 2010 at 3:05 am
    Reply

    Thank you so so so much! I used the regedit instructions. :-)

  4. firefly4f4 said on April 22, 2010 at 7:55 am
    Reply

    I can do everything except the “about:config” step. That variable simply doesn’t appear. The only similar thing that appears is microsoft.CLR.auto_install, which is set to false. I’m using firefox 3.6.3.

    Note that I followed the instructions that used regedit first, though.

  5. Kainsmoney said on March 20, 2010 at 9:22 pm
    Reply

    Most of the times , i have all plugins disable , as they are worthless .

  6. polocanada said on December 30, 2009 at 6:13 pm
    Reply

    Thank you thank you thank you… you just made my day.

  7. Kshatriya said on December 23, 2009 at 12:52 am
    Reply

    Awesome solution…Hats Off to all TechWizards…!

  8. z.Yleo77 said on November 13, 2009 at 5:50 am
    Reply

    error… it can’t work in my pc..

  9. Matt said on October 18, 2009 at 12:37 am
    Reply

    Many commenters are wondering what harm these Microsoft backdoor add-ons cause with Firefox. Here is a possible answer:

    http://annoyances-resolved.blogspot.com/2009/10/battle-of-two-softwares-microsoft-vs.html

  10. Fede said on October 17, 2009 at 3:55 pm
    Reply

    How the hell the firefox code that i install several days ago was prepared to uninstall this update from MS from a couple days?
    I remmeber accept the update from MS but i don’t remmeber accept firefox update his code to detect this extension and proceed to automatically uninstall whitout asking me…

  11. Justin said on October 17, 2009 at 8:09 am
    Reply

    Help? I’m coming in a bit late to this- I dont know if this stuff even APPLIES anymore. I’d never noticed or even heard of Microsoft .Net Framework Assistant until just a few mins ago. I was watching something in Win Media Player that I’d gotten online, I closed it, then I saw a message from Firefox saying that “Microsoft .Net Framework Assistant is unstable” or something like that. Asked me if I wanted to restart Firefox. So I did. Then googled it. Most of what I find seems to be from back in Feb – April, yet some is more recent. Was this situation resolved since then? Because I dont even see Microsoft .Net Framework Assistant listed in my add-ons at all. Yet, I got this message of danger or instability… Someone fill me in???
    -J

  12. steve said on September 14, 2009 at 2:51 am
    Reply

    Did it the same way Dee did it. Works like a charm. I wouldn’t recommend David’s way as it seems you are just giving MS another chance to screw with your cpu.

  13. David said on August 19, 2009 at 8:16 am
    Reply

    If you guys use Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.2) Gecko/20090729 Firefox/3.5.2 , you can go to this page https://addons.mozilla.org/en-US/firefox/addon/9449 to upgrade the .Net Framework Assistant, and then you can uninstall the extensions.

    Hope this can help!

    1. John said on September 13, 2011 at 8:09 pm
      Reply

      David, from all that I have read here, yours is the best and most “clean” solution to the problem. Good work!

  14. Charles said on August 7, 2009 at 7:22 pm
    Reply

    Quick solution: install the recent Microsoft patch “Update to .NET Framework 3.5 Service Pack 1 for the .NET Framework Assistant 1.0 x86 (KB963707)”. After I installed it, the uninstall option became available. I uninstalled it, and poof, it was gone.

  15. david gunnells said on July 6, 2009 at 9:06 pm
    Reply

    It will also append to firefox’s useragent string. :(

  16. Arno Teigseth said on June 22, 2009 at 5:08 pm
    Reply

    AutoCAD 2010: Also got this installed without seeing it anywhere. I’m going to complain to Autodesk.

  17. Transcontinental said on June 1, 2009 at 10:17 am
    Reply

    There’s an interesting article on the Washington Post regarding this adventure, http://voices.washingtonpost.com/securityfix/2009/05/microsoft_update_quietly_insta.html
    Says it all and said by a security professional, for those who could still doubt…

  18. Dee said on June 1, 2009 at 2:40 am
    Reply

    Run > “regedit”)
    <2. Goto “HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Firefox\extensions”
    (or “HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mozilla\Firefox\extensions” for 64-bit versions of Windows
    <3. You’ll see “{20a82645-c095-46ed-80e3-08825760534b}”. Right click it and click Delete.
    <4. Restart Firefox.

    BINGO! This worked. It’s now gone! Thank you!

  19. Dee said on June 1, 2009 at 2:22 am
    Reply

    # Make sure Firefox is closed.
    CHECK!

    # Go to C:\WINDOWS\Microsoft.NET\Framework\v3.5\Windows Presentation Foundation\DotNetAssistantExtension in Windows Explorer
    and delete everything in that folder but keep the folder name.
    CHECK!

    # Start Firefox.
    CHECK!

    The add-on should not be in the list anymore.
    AHHHHH, WE HAVE A PROBLEM. It’s still there! Now what?

  20. David said on May 25, 2009 at 10:56 am
    Reply

    Wow. thank you so much! I did this and my firefox instantly ran faster. I was wondering why my internet was so slow lately. I thought it was my cable, but i realized it was firefox. Doing the regedit way deletes it from the addon menu, but doing it as the original author stated actually made my firefox run faster, thanks!

  21. Piel said on May 24, 2009 at 11:46 am
    Reply

    Easier way to uninstall:

    1. Open Regedit (Start > Run > “regedit”)
    2. Goto “HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Firefox\extensions”

    (or “HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mozilla\Firefox\extensions” for 64-bit versions of Windows
    3. You’ll see “{20a82645-c095-46ed-80e3-08825760534b}”. Right click it and click Delete.
    4. Restart Firefox.

  22. Wize said on April 26, 2009 at 11:32 pm
    Reply

    I have disabled it. It was causing firefox to act funny (after a while of use, it would stop loading webpages)

  23. nobody said on March 1, 2009 at 7:13 pm
    Reply

    Also in my add-ons > plugins page:

    Microsoft DRM
    DRM Netscape Network Object
    Microsoft DRM
    DRM Store Netscape Plugin

    Where did these come from?

  24. Transcontinental said on February 11, 2009 at 7:43 pm
    Reply

    In Firefox Extension Manager’s Plugins’ Tab, appears the following related plug-in :

    Windows Presentation Foundation (WPF) plug-in for Mozilla browsers

    I’ve disabled it, assuming that it is correlative of removing Microsoft .Net Framework Assistant Firefox extension. Is that correct ?

  25. Transcontinental said on February 11, 2009 at 9:34 am
    Reply

    Taomyn > Well, when I disabled JQS from Java’s control panel, I noticed immediately that JQS Firefox extension had been removed.

    The thing to avoid is to remove/disble JQS Firefox extension manually (that is therefor before disabling JQS from Java control panel), because doing so may lead to problems with further Sun Java installs.

    Concerning the .Net Framework Assistant extension, the annoyance of its install without notification is even more obvious than that of JQS since the former offers no mean of removal, and that this post reflects the counter-measures processed by enlightened thoughts ;)

  26. Taomyn said on February 10, 2009 at 9:02 pm
    Reply

    @Transcontinental, sorry but know. Two separate installations on an XP and Vista system of Firefox v3.06 and Java 1.6_12, neither has “JQS” enabled and both still have the extension.

    I really wish Mozilla would describe how to get rid of these properly – I looked around and it seems the extensions are installed as NS1:installLocation=”winreg-app-global”, which I think is what tells Firefox to disable the uninstall button. I guess because it’s meant to be a global extension. I can’t seem to find out much more about it.

  27. Transcontinental said on February 10, 2009 at 5:39 pm
    Reply

    Taomyn > Sun’s Java Quick Starter Firefox extension is automatically removed once Java Quick Starter is disabled from Java’s control panel.

  28. Taomyn said on February 10, 2009 at 5:05 pm
    Reply

    Firstly, I totally agree with all the comments against the way this has been installed but I don’t recommend removing it this way.

    Simply disable it.

    Why? Because another update to .NET will simply re-install it again and you’ll have to remove it all over again. Disable it and no matter how many times MS updates it, it won’t run (unless they rename the extension I suppose). Hopefully they will take the hint and make the installation more transparent.

    By the way, they’re not the first – recent updates to Sun’s JVM (builds 10 onwards I believe), have done exactly the same, again can’t be “uninstalled” and even worse include code that automatically runs a service and also runs the JVM process when Firefox starts up.

  29. Jojo said on February 10, 2009 at 1:09 pm
    Reply

    I still don;t understand what it is exactly that this extension does nor how it gets installed without my approval. Does it come with Silverlight maybe?

    I do notice that much of the MS site works in FF these days. Maybe this extension is what allows that?

    And does this add-on compromise FF security in any way?

  30. Transcontinental said on February 10, 2009 at 10:23 am
    Reply

    Microsoft .Net Framework Assistant in Firefox and Java Quick Starter (extension and system-wide) : two intrusions less, two.

    I think the dichotomy “good guys”/”bad guys” is a false concept, as we are all both. OK, some may be more this or more that, but to who is it up to decide?

    Whether it be Microsoft, Google, Apple, Yahoo etc. etc., the golden modern oil is information, they all want to know what we do on the Web. Fair enough to counter-strike, with a smile and with modesty :)

    No, I’m not paranoid! I mean, just enough, I hope!

  31. Dante said on February 10, 2009 at 2:32 am
    Reply

    Just tried to read the MicroShaftese language at http://msdn.microsoft.com/en-us/library/cc716877.aspx

    They basically installed a backdoor function into your browser. I’ll bet it has all the problems of ActiveX. And MicroShaft is forcing it all down your throats.

    1. Raven said on September 28, 2014 at 9:06 pm
      Reply

      Great. The first person who seems to understand that this fake language means absolutely nothing. So Microsoft “installed a backdoor into your browser”. Great. Who cares? So have many other places. We are not asking about security bullshit. We already know that some “vulnerability was discovered” (mainly, this vulnerability is the fact that you are using Windows). Whether or not a “vulnerability was discovered” or if “the plugin is insecure” is irrelevant to whether you should uninstall Flash or Java, since the answer to that question is always “No” unless you don’t actually use the Web. What is the *ACTUAL* answer to “Should you uninstall .Net Framework”. There are many websites that just show an empty, blank white screen, no 404, when “loaded”. Is that because there is no “.Net Framework”? Is it because a Service isn’t running? Etc. Since you seem to be the literal one person who is aware that no, “This article on Microsoft’s website” does NOT tell you what this is or what this does, are you then able to actually tell us that yourself?

      The most POSSIBLE information on this so far is “something very vaguely to do with XML”. Well that’s great…. but XML already exists and already works (sometimes). So the correct answer to “What does this do”, will include the words “The Internet will break if you remove this,” “The Internet won’t break if you remove this,” and/or “Some of the webpages that normally do not load and show a blank white screen with not even a 404, are doing so (or are not doing so) because of this plugin (or because of the lack of this plugin).” Or “Some of the websites where you click the button and nothing happens, are doing so because of this plugin or because of a lack of this plugin.”

      Can you be the only person ever to actually answer the question everyone is asking??!?

  32. Avatar said on February 10, 2009 at 2:31 am
    Reply

    it gives OneClick support to firefox and people that has installed .net but that use firefox should not remove it. it allows for quick streamlined .net app installs.

    1. Raven said on September 28, 2014 at 8:57 pm
      Reply

      WHAT THE FUCK IS “CLICKONCE SUPPORT” AND “.NET APP INSTALLS”?

      INSTALLING A PROGRAM ON MY SYSTEM HAS NOTHING TO DO WITH FIREFOX OR ANY BROWSER NOR WITH ANY PLUGINS FOR IT, EXCEPT IN CASES WHERE THE WEB PROGRAMMER IS BAD ENOUGH AT PROGRAMMING TO PUT SOME KIND OF JAVE/ETC. CODING IN THE BUTTON RATHER THEN A DIRECT DOWNLOAD LINK.

      THERE IS NO SUCH THING AS SOMETHING THAT CAN “ALLOW FOR” ANYTHING NOR AS SOMETHING THAT CAN BE “STREAMLINED”. YOU ARE CLEARLY TRYING TO ADVERTISE A COMPANY BUT TRY WRITING SENTENCES PROPERLY FIRST, WITH ACTUAL CAPITAL LETTERS.

      DOES THE INTERNET WORK WITHOUT THIS PLUGIN? WILL ANY WEBSITE EVER HAVE ANY PROBLEM THAT RENDERS THE WEBPAGE 100% COMPLETELY UNUSABLE OR DOES NOT LOAD THE PAGE BECAUSE THIS IS NOT INSTALLED? ARE ANY OF THOSE WEB PAGES OWNED BY SOMETHING OTHER THEN MICROSOFT?

      “WHAT IS .NET FRAMEWORK? WHAT IS WPF?” ANSWER THE FUCKING QUESTION AND DO NOT TALK ABOUT DEVELOPERS OR “CLICKONCE” OR SOME MARKETING-ADVERTISING BULLSHIT (such as “ClickOnce” which is not a real thing) OR ABOUT THE UNDERLYING PROGRAMMING LANGUAGE USED OR ABOUT *anything* BEISDES WHAT THIS ACTUALLY IS (without using those words) AND WHETHER OR NOT IT IS NEEDED.

      FOR REFERENCE, THE ANSWER TO THE SAME QUESTIONS ABOUT FLASH OR JAVA IS “YES!!!!!!!!!!!!!”. NOT “I RECOMMEND YOU UNINSTALL THIS BECAUSE IT HAS SECURITY FLAWS” OR “YOU NEED THIS IF YOU ARE USING FLASH AND JAVA APPLICATIONS”. *NO ONE* IS “USING FLASH AND JAVA APPLICATIONS”. WEBSITES USE THEM. REMOVE FLASH, THE INTERNET BREAKS. REMOVE JAVA, THE INTERNET BREAKS. REMOVE MICROSHIT, AND……? WHAT IS IT???!???

  33. Jojo said on February 10, 2009 at 12:24 am
    Reply

    Many question need answering!

    WHAT is this add-on for? Does it cause any harm or security exposure? WHY would I want to remove it? What would guarantee that MS wouldn’t just add it it back in? And finally, HOW did MS get this add-on into FF in the first place? I don’t recall approving it.

    1. Martin said on February 10, 2009 at 12:55 am
      Reply

      JoJo:

      1. Well the add-on is described here: http://msdn.microsoft.com/en-us/library/cc716877.aspx
      2. You might want to remove it as you did not install it actively in first place.
      3. No guarantee
      4. It is apparently part of an update of the Microsoft .net Framework 3.5

      1. Raven said on September 28, 2014 at 8:48 pm
        Reply

        Nope, that doesn’t really tell you what it is. Firefox can already read XML (except in some glitchy cases). This is a very simple question to answer:

        What happens if I uninstall Flash?
        Videos will not work and some websites that you want to download from will not be able to download.

        What happens if I uninstall Java?
        A large amount of websites will not work – they will have buttons (such as “rate this post” or “delete this post” or “install now” or “submit this form” buttons) that do nothing. Other websites will work, but will look funny, have extra steps, and may be difficult to navigate.

        What happens if I uninstall .NET Framework and/or WPF?
        Answer:
        ….?

        The article says “ClickOnce,” which is likely a retarded Microsoft term, so basically only Microsoft websites will not work? DOES ANY WEBSITE ACTUALLY USE THIS PLUGIN?

        Simple question…
        Developers and high-level techies just don’t know how to answer simple questions…

  34. Paul said on February 9, 2009 at 11:48 pm
    Reply

    What dose it do, Why remove it?

    1. Tom195 said on September 11, 2009 at 7:08 pm
      Reply

      Because it shouldn’t be there in the first place. No add-ons should be installed without your approval/acceptance. This one bypasses all of that somehow.

      Also, it isn’t complete or functional.

      ANY software, including add-ons, that are installed and not being used are just wasting memory.

      You could go around installing every piece of software you can find and then sit around wondering why your computer is so slow…

  35. jnC said on February 9, 2009 at 11:42 pm
    Reply

    what does this addon???

    just wonder…

  36. Dante said on February 9, 2009 at 11:21 pm
    Reply

    So Microsoft finally found a way to “Embrace, Extend and Exterminate” Firefox. By taking over Firefox codes.

Leave a Reply

Check the box to consent to your data being stored in line with the guidelines set out in our privacy policy

We love comments and welcome thoughtful and civilized discussion. Rudeness and personal attacks will not be tolerated. Please stay on-topic.
Please note that your comment may not appear immediately after you post it.