Have you tried switching your router off and on again and then connecting by ethernet?
Are your network drivers up to date - check in device manager.
You could try resetting the Internet Protocol by using the Fix it in this article.
If this doesn't work delete your network from available networks then connect your pc by ethernet cable to the router and go through the process again.
There may be a chance that your antivirus is blocking access. You could try temporarily disabling this while you try to connect.