• Reboot
• hold SHIFT
• select your inage on Grub menu
• press "e" to edit
• in the line starting with "linux" add int=/bin/bash to the very end
• ctrl+x to reboot
• your system will boot to passwordless root shell
• mount -o remount,rw / (make your partition writable)
• some people do: chmod 640 /etc/shadow file other just copy: cp /etc/shadow- /etc/shadow to eliminate it from th game
• analyze what you have by: less /etc/passwd
• determine what needs to be changed by: passwd USER

Scenario:

• Ubuntu server installed as a virtual machine and connected via bridged network adapter to a network
• pinging and services are accessible from Windows machines only by IP address, no name resolving, no DNS server on duty, just NetBIOS names
• can't ping Windows hosts from Ubuntu by their host names either

Resolution:

• on Ubuntu server: sudo apt-get install samba (then you can ping and access services on Ubuntu from Windows hosts by a hostname)
• to be able to ping Widows hosts from Ubuntu you need t