hi, we recommend that you use an operating system that is kept up to date with security updates. http://robert.ocallahan.org/2017/01/disable-your-antivirus-software-except.html

Read the reply and article noted. In 37 years of working on computers I have never read such a pile of self righteous crap in my life. I was looking for a legitimate reply as to which F/A/V software would work the best with Firefox, and what I read was some of the most over the edge ridiculous comments I have ever heard on the subject. If you folks are indicative of the quality of responses to questions submitted to Mozilla than I am truly wasting my time.

Everyone has their own favorite. I use Norton, another uses something else. What you need to do is read the reviews, and check what each program can do for you and your system.

Note that some programs have caused problems for Firefox. In most cases, this is from a FF upgrade, and the programmers need to update their protection programs to work again.

This is a volunteer-staffed forum and no one here speaks on behalf of Mozilla regarding third party software recommendations. Individuals certainly might have their own preferences.

I'm not aware of any mainstream security software that doesn't work with Firefox, save for one. Some general observations:

• If there are particular features that require an add-on, those features might not work in Firefox due to changing support for plugins (now nearly none) and extensions.
• Some programs can cause severe crashes from time to time, usually as a result of overly aggressive IPS modules. (And see: Old versions of Websense cause startup crashes in Firefox)
• Some program features may be incompatible with the newer multiprocess architecture, either alone or when other security software also is running on the system (e.g., certain versions of Malwarebytes Anti-Exploit can block all requests from Firefox when Norton Internet Security/Norton 360 is running on the system).
• Programs that operate as a "man in the middle" of HTTPS connections sometimes fail to set up Firefox automatically to trust their fake site certificates, or munge the compression. Tips on a number of such programs are provided in this article: How to troubleshoot security error codes on secure websites.

I am not sure Mozilla is likely to make any such recommendation or judgment.

Volunteers and ex staff are possibly more likely to express personal opinions and observations about known issues than anything Mozilla would say officially.

You apparently are posting using a machine running XP and may be aware that Firefox is not supporting that OS any longer. Also the vendor MS is not really supporting XP it is EoL although there may have been very recent media reports about a patch being back-ported to XP by MS after some high profile ransomware incidents.

• See also Firefox has ended support for Windows XP and Vista

Recent media reports

• TheRegister:
  74 countries hit by NSA-powered WannaCrypt ransomware backdoor: Emergency fixes emitted by Microsoft for WinXP+
  http://www.theregister.co.uk/2017/05/13/wannacrypt_ransomware_worm/
• BleepingComputer:
  Microsoft Releases Patch for Older Windows Versions to Protect Against Wana Decrypt0r
  https://www.bleepingcomputer.com/news/security/microsoft-releases-patch-for-older-windows-versions-to-protect-against-wana-decrypt0r/
• KrebsonSecurity: Microsoft Issues WanaCrypt Patch for Windows 8, XP
  https://krebsonsecurity.com/2017/05/microsoft-issues-wanacrypt-patch-for-windows-8-xp/

It is also worth noting Firefox is multi platform. It runs also on Android, Macs and Linux.

If you wish to see if anyone is likely to make an official comment then may I suggest you please look at the main fora and mailing lists and consider repeating your question over there

• https://www.mozilla.org/about/forums/

If you do post a question on one of the main official fora feel free to paste the link in to a reply in this thread, as I am sure many people would be interested in the discussion

Since you run the ESR version of Firefox, you will still need to keep your old plugins that you expose to the web up-to-date. I notice you have old versions of the Adobe Acrobat plugin. To update those:

Adobe Reader or Adobe Acrobat XI (11)

Inside the Adobe product (not through Firefox), use the Help menu to Check for Updates. If that doesn't work, you can download an updater from the release notes page:

http://www.adobe.com/devnet-docs/acrobatetk/tools/ReleaseNotes/11/11.0.20.html

Adobe Reader or Adobe Acrobat X (10)

Security updates for this series already ended. If you haven't uninstalled this version, try updating from inside the product as described above. If you need an updater, try the release notes page here:

http://www.adobe.com/devnet-docs/acrobatetk/tools/ReleaseNotes/10/10.1.16.html

Hi   !
Speaking for myself :   using Windows Defender plus the safest browser on the planet,   I feel like I'm in Fort Knox. Tried various anti-virus programs, which only caused problems. Would you take a look at this, please :
http://tech.firstpost.com/news-analysis/ex-mozilla-firefox-developer-says-anti-virus-software-does-more-harm-than-good-359798.html

To everyone that posted 'helpful' comments. I appreciate your feedback. Although I am primarily still on XP I do have a duel boot system with Win 7. I will be moving everything to the new OS over the next few months and I appreciate the assistance. Being on computers for almost 40 years I actually am one of those users that primarily use huge spreadsheets and accounting software that doesn't have to have the newest of everything. I will move away from XP kicking and screaming...but I am moving.