Web pages not loading

Hi
Some websites will not load on either Chrome, Firefox, Edge or Vivaldi.
I have cleared the history and cache
Tried both OpenDNS & Google DNS
Full scan with Bitdefender AV, Malwarebytes Anti-Malware & Spybot Search & Destroy: nothing found
Turned firewall off
Uninstalled and re-installed each browser.
Have removed extensions/plugins but the problem persists.
I have found that if I paste the website link into the address bar the page
partially loads but 'circle' continues to rotate for several minutes.
If I right click on the link from another page and select 'Open link in new tab' I get:
This site can't be reached. The connection was reset (ERR_CONNECTION_RESET)


On occasional instances with some websites when I right-click to open a link in a new tab it'll sit
there for a few minutes and then redirect to http://www.traffic.outbrain.com but this never loads
then it goes to: 'This site can't be reached. The connection was reset (ERR_CONNECTION_RESET)'.


Last week I had another problem whereby if I clicked on a link or a folder I'd get the message:
'This file does not have a program associated with it for performing this action. Please install
a program or, if one is already installed, create an association in the Default Programs control panel'.


At that (on TenForums advice) I re-installed Windows 10 but kept my Data and installed programs.
This solved the association problems but now I have this new one.
Any ideas?

I guess if no-one has any ideas how to fix this then all that's left is a complete re-install of Win10

Hi
Further to my previous post I have now done a fresh install of Windows 10 Home edition. "This will solve the browser problem" I thought.
Well, believe it or not it hasn't. To reiterate:


Some websites will not load on either Chrome, Firefox, Edge or Vivaldi.
I have cleared the history and cache
Tried both OpenDNS & Google DNS
Full scan with Bitdefender AV, Malwarebytes Anti-Malware & Spybot Search & Destroy: nothing found
Turned firewall off
Uninstalled and re-installed each browser.
Have removed extensions/plugins but the problem persists.
I have found that if I paste the website link into the address bar the page
partially loads but 'circle' continues to rotate for several minutes.
If I right click on the link from another page and select 'Open link in new tab' I get:
This site can't be reached. The connection was reset (ERR_CONNECTION_RESET).


Now oddly, some websites load as normal, some load partially in that the circle continues to revolve on the tab and parts of the website
are blank (such as some pictures) and some websites do not load at all and lead to '(ERR_CONNECTION_RESET)'.


I tried the same sites with a laptop: on wifi no problem, on ethernet no problem.
I've updated drivers, especially the Realtek PCLE GBE Family controller, all to no avail.


Does anyone know of some diagnostic software that will show where the problems occur?
I know that Firefox have some developer tools but I'm unfamiliar with there use.
Help!

OK, I appear to have solved the problem. I downloaded TCP Optimizer which suggested that I change the MTU from 1500 to 1432.
Following a reboot I was relieved to discover the problem had gone!

OK, further to the above I have just done fresh install of Win10 on another PC.
Guess what. Windows incorrectly set the MTU to 1500 which gave me the same problems as original post here.
Once again I used TCP Optimizer and changed MTU to 1432.
Now no problems!
So that's another (albeit odd) Win10 bug unless it's some issue with my router not connecting to Win10 installation. I don't know - this is not my area of expertize.
If anyone has any thoughts on this I'll be interested to hear them.