Meaning W7 is no longer support and you need to use a newer supported O/S to most likely access those sites is what it sounds like.

WestEnd said

Meaning W7 is no longer support and you need to use a newer supported O/S to most likely access those sites is what it sounds like.

I am sure Mozilla will not let that happen because Win7 is still a widely used OS and it was working till last few days. Moreover, this error occurred earlier in case of other and got resolved tinkering with Antivirus softwares. Awaiting for resolution in anticipation :)

Not right now Windows 10 is overtaking Windows 7 now. And support for it is already going away. Even I went and update all my family's computer to Windows 10 for better update and securities. Mozilla has no control over W7 that is a M$ issue. So if you want to use W7 that is your choice but your system will be a primary target for hackers once support ends. As to what A/V you using that could be a factor but if it was left in default and still had problems then it is adding more problems then it is helping. I always used Microsoft MSE and now Defender and Windows Firewall and had no A/V or Firewall issues.

Windows 7 is still supported by Microsoft until January 14, 2020. It is Windows Vista and XP that support has pretty much ended for regular users.

It is still a very popular OS and more favoured compared to the crap Windows 10. The only reason why I would use Win10 over Win7 is due to DirectX 12 for games.

Win7 is far more popular compared to Win10 according to Steam survey http://store.steampowered.com/hwsurvey/

Anyways let's get this thread back on topic.

vivek.pw said

On win7pro 64 bit PC, suddenly error staring on all websites including Mozilla stating "Your connection is not secure". No antivirus installed on this PC therefore existing resolutions are not workable. Only windows defender kind of programs were installed. This problem appears to have come up after some windows updates. Not sure which updates.

Maybe something in https://support.mozilla.org/en-US/kb/what-does-your-connection-is-not-secure-mean will help.

Also make sure your date and time is correct on your Windows. https://support.mozilla.org/en-US/kb/troubleshoot-time-errors-secure-websites

Hi WestEnd, although Windows 7 "mainstream" support has ended, it is on "extended support" through January 14, 2020 according to:

https://support.microsoft.com/en-us/help/13853/windows-lifecycle-fact-sheet

So like many people, I'm in no rush to switch from Windows 7 to Windows 10 and I'm still counting on Microsoft to provide critical security updates (even if other kinds of updates are no longer made available) for the next 3 years.

Thanks for discussions and support. The problem got resolved by its own. The error is gone and it is working fine now. Not sure if some background update worked or something else. Thanks again.