It would help a lot if you take some time forming real sentences when you post.
As for why you can't ping your friend, it's possible that his router is set to not answer pings. The most likely reason that you cannot join each others server is because the necessary ports are not forwarded.
The other thing it could be is your network adapter bind order. You have to switch it so that hamachi is the preferred connection or your games will try to use your normal internet connection instead of the hamachi VPN. Even if hamachi is listed first try switching it to the 2nd spot then back and reboot. To see your bind order open control panel then open network connections. From there click on the advanced menu and pick advanced settings. That will open a window that will have the bind order, you can change the order by highlighting a connection and pressing the little arrows beside the list.