How to fix internet connection?

I have a problem with my internet connection. As you can clearly see I'm using the Internet to ask this question but when I was removing an add on from the browser using avast it said it couldn't connect to server and when I tried to install jdownloader using web installer it also couldn't connect. I'm using windows 7 x64, connected by wi-fi on lenovo g500s.

That server maybe down for you
try back.

Restart your internet by switching off the power to the router.

Hey dude try to reconnect your internet connection and block adds through setting of your browser.