I have Windows 7 as guest OS on my Ubuntu 12.04 host through Virtualbox. I use dial-up connection (ppp0) through a USB dongle on host machine to access Internet. However, when my host is connected to the Internet, guest (Windows 7) is not able to connect to the Internet, either using NAT or Bridge method in Virtualbox. What could be the problem?
You are connected to the internet using ubuntu right? You need to be connected to the internet using ubuntu and then, access to this connection is given to the virtual machine. So just check. It works on an arch linux virtual machine, so I can't imagine that it won't work in a windows virtual machine.