I installed VirtualBox on a Windows 7 PC and installed Xubuntu (Ubuntu with XFCE) on it. Now on the Windows, I am connected to the internet through a LAN which automatically authenticates to connect to the network(because its my work computer). I have also installed the guest additions on this virtual machine (Xubuntu). I tried both NAT and bridging to set up internet connection but I still cannot connect to the internet.

For NAT: The browser doesn't say website not found but it keeps trying to load it forever and the network status monitor (the one provided by VirtualBox) doesn't show any green light (no incoming packets).

For Bridging: Same as for NAT but the network status monitor shows incoming packets and outgoing packets. But internet still doesn't work.

I tried a lot of different things but none worked.