enabling root on ubuntu

I strongly suggest you read this help page for implications of enabling a root.
Just adding this page for quick reference and some lazy users like me

Enabling root


sudo -i

sudo passwd root


Disabling root

sudo passwd -dl root

ubuntu software center - check your internet connection

While trying to install a package from Ubuntu software center, I received "Check your internet connection" even though the connection is fine and I am able to access the internet.

Even if the issue with the mirror server, it looks like a wrong alert. Though this is related to the connection with the mirror, problem is not your connections.

After opening Ubuntu Software Center

   -> Edit

         -> Software Sources

Select a different server from the list.

Best thing might be to auto select a best suitable mirror