Can't boot after update, purple/black screen

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http://askubuntu.com – I am dual-booting Ubuntu and Windows 7. Yesterday I've installed many updates (including many system software) on Ubuntu. After the restart it couldn't boot anymore. I just get first a purple screen and then just a black screen, when I start the normal boot. When I can choose the recovery mode, I can boot Ubuntu. I have tried to fix all the packages in recovery mode but that doesn't help. (HowTos)