i just upgraded from squeeze to wheezy on a virtual box installation. Now anything requiring a network doesn't work and I get "network is unreachable" message.
I ran #ifconfig and nothing comes up.

#cat /etc/network/interfaces outputs this(just typing it out, can't copy/past):

#the loopback network interface
auto lo
iface lo inet loopback

#the primary network interface
allow-hotplug eth0
iface eth0 inet dhcp

----end file----

#lsmod shows that e1000 module is loaded with 0 using. Not sure if that's the right module, though.

The network settings in virtualbox is :

Attached to: bridged adapter
Name: Realtek PCIe GBE Family Controller
(Greyed out)Adapter type: Intel Pro/1000 MT desktop (82540EM)
Promiscuous mode: deny
Cable connected: checked

----------

During boot I see something about statefile /run/network/ifstate failing to be opened.
If i run ifup eth0 or ifup -a it says "failed to open statefile /run/network/ifstate: no such file or directory"

I'm not a linux/debian/networking pro so am kind of lost. Appreciate any help.

Try running