Minecraft Cannot Connect to Server (java.io.IOException)

How are you connecting? Internally or externally (are you getting your ip from the ipconfig command in the command prompt or from a website). If you're not, try connecting internally. Also, I'd really learn how to port forward (there are thousands of tutorials for Minecraft port forwarding everywhere) as Hamachi lets viruses in everywhere and can really mess up an internet connection. Also, keep your firewall on!

Since the server is hosted on a different computer, you cannot use localhost to connect to the server on your laptop from your new pc. localhost is only for server host on the same computer.

To connect to your server host on the laptop from a different pc, you should first find out the local ip address of your laptop.

You can check your local ip address of your laptop by browsing this website from your laptop: "What is my Local IP address?" or check it manually using cmd from your laptop (How To Check Your Local IP). The local ip address maybe like : 192.168.0.100

Now you can connect to the server using the local ip of your laptop from your new pc. If you want to use your public ip, you have to set your laptop as DMZ host , Virtual Server or forward port to your laptop. This has to be set at your router.