Solution for AVG users
Issue: User is unable to access the internet; ipconfig output is empty for all primary network interfaces.
How To Fix/Instructions:
Mainly seems to be caused by the presence of AVG Network Filter Driver. Diagnose by the running the following from an elevated command prompt:
netcfg -v -s n
If gr_avgfwfd is present, have them uninstall with
netcfg -v -u gr_avgfwfd
then the usual combination of
netsh winsock reset catalog
netsh int ipv4 reset reset.log
Finally, reboot and verify connectivity using ipconfig or Details tab.