First off, try running disk cleanup to clear your temp files and browser cache. That may help.
If you check your network connection when this error occurs, and it is connected, this could be a sign of what's called a browser hijack, a sort of malware infection. There are some things that install on your system and prevent you from accessing sites that they deem harmful (to themselves)..
For example, can you go to windows update and update your system? Is your antivirus updating successfully?
If not, I recommend you go to www.malwarebytes.com and download their free Anti-malware software, update it and run a scan of your system. Allow it to fix anything it detects.
It will automatically save a logfile.
Then run a full scan of your system with an updated AntiVirus scanner.
You might wish to consult this link
as well, if you have any further problems...
I hope this information allows you to resolve this issue. If you need further assistance, please post back with a comment to this thread.
If I've managed to answer your question or solve a problem, please take a moment to kindly rate this post....thanks!