Certificate error: navigation blocked.

Hello, I recently performed the upgrade to windows 10 and found it hopeless. I could not get internet connectivity and many programs would not work. I tried some troubleshooting but gave up and reverted to 8.1. That worked well except that IE 11 has an error that I cannot resolve. All sites that I try to access give me ; Certificate error: Navigation blocked, even the Microsoft site!
I have tried each of the security settings under Internet options but no joy, system time is correct.
I am currently using Firefox and there are no problems with it.
Anyone experienced this, any suggestions?
Alex.

Resolved, updated PC (Lenovo helix) with latest drivers, reinstalled win10 and all is well.