[ubuntu] Keyboard won't respond in recovery screen

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http://ubuntuforums.org – When I end up by some misfortune at the recovery screen (black, earth in foreground, stars, menu at top left), the keyboard will not respond. All I need is "Enter", but it will not respond to pressing the Enter key or any other key. This has happened twice. The first time I simply rebooted a few times, and it finally went back to the regular log-in screen on it's own. The second time (tonight), lots of reboots, no happy... Then started in Windoze (I can switch boot drives by switching one on and the other off) and worked fine. After about an hour more of frantic efforts, (Hardware)