'Your connection is not private.'?

[Psittaciformes]

Do we have any computer geniuses here?
I haven't used my computer that much lately, haven't been on it for a couple of days or so.
Yesterday everything worked fine for 5 minutes, then I reloaded a page and I just kept getting this message saying my connection isn't private.

YouTube, Google, Flickr, basically any website I use but this. Should I be concerned or could I accidentally have changed a setting on chrome?

Edit: I just tried it on Internet Explorer and I still get a warning, but on there I can either continue on the website or close the webpage.
Could I have changed something on my computer without realising, or should I start making calls?

 

[Minimaker]

I just googled it and this came up-don't know if it would help or not but worth a try:
Receiving 'Your Connection is not Private' message.... - Web Browsing/Email and Other Internet Applications

If none of that works, google it and read through a few more suggestions until you hit on something that works. Sorry I can't be of more help.

 

[Psittaciformes]

Well, Google doesn't work either.
I managed to get your link to open and I tried going incognito, now it just says 'No data received', and I can't even post replies from my computer now.

What is going on?!

 

[JerseyWendy]

Can you run your computer in SAFE MODE and do a Virus Scan??? Which virus software do you have installed? And what platform are you running (Mac, Windows...which version of Windows?)

 

[Psittaciformes]

Running McAfee at the moment, how do I go into safe mode?

Windows 8.1

 

[JerseyWendy]

Here is a step by step tutorial:
5 Ways to Boot into Safe Mode in Windows 8 & Windows 8.1

 

[JerseyWendy]

Once you've run a scan, and if it comes back clean, but the problem persists, you can try 'System Restore'.
How To Use System Restore in Windows 8 or 8.1 [15 Min]

 

[Psittaciformes]

Thank you so much Wendy! I really appreciate it.
I was considering doing a complete reset of my computer, but if that's not necessary, then great