Yes it can be solved, the problem is not related to Windows 7 or XP. It is related with connection.
It happens because Re-Volt requires some PORTS in your modem-router to be OPENED to use the internet, and they are probably closed.
To fix it you can just come one of these days in RV House and I can help you to open them, or if you want to do it alone, here I'll give you a website which contains instructions on how to open the ports. Just search for your router manufacturer and model for specific intructions.
You can also search in YouTube.
http://www.PortForward.comGreetings.