The System is running in low graphics mode, Your Screen, graphics card,and input device settings could not be detected correctly. You will need to configure this yourself.
晚上有很多说法，试了没用，最终解决办法是重装显卡。
点击ok之后选择，重装显卡驱动，进入命令行模式，输入一下代码
[cc]sudo apt-get install nvidia-current[/cc]
待安装完成之后重启即可
[cc]sudo reboot[/cc]
参考：http://askubuntu.com/questions/141606/how-to-fix-the-system-is-running-in-low-graphics-mode-error