Matthew is having issues with WiFi when he moves to the second floor. Leo says it's important to remember that WiFi is about 150' in distance. But things can get in the way and dilute the signal, especially metal. An extender will help but you want an extender that is made by the same as your router. Leo has three of them. ActionTec is what Matthew's router is and they do address extenders here. That's the most affordable option. Then there's powerline networking that uses the electrical cable in your walls as networking cables. Lastly, if you could get into the walls, laying Ethernet cable is the best. But that can be expensive.
Matthew is having issues also with his Lets play videos. Leo says it sounds like bandwidth issues.