Linux OS (Ubuntu 12.10) starts up (user login, my personal picture of a beautiful Norwegian fjord-landscape fills the background), but the main menu on the left side, and the pictograms (battery state etc.) at the upper right corner of the screen, do not show up. This occurred yesterday quite suddenly after six or seven weeks working with Ubuntu 12.10. Then I started in recovery mode and performed a file system check (fsck) but that takes hours and finally a message ¨Sorry Ubuntu has experienced an internal error etc¨ appeared. How can I determine what has gone wrong and eventually, how can I solve it? So that I can work again using Ubuntu 12.10 (on a dual-boot system, Intel i7, ASUS P8P67 motherboard).