[求助]不能启动图形界面了!

JusticeFreedom

今天早上一开机，Xserver就不能启动
蓝屏上有这样几行字
GDM：Xserver not found：/usr/x11r6/bin/X :0 -br -audit 0 -auth
/var/lib/gdm/:0 Xauth -nolisten tcp vt7
Error:Command could not be executed!
Please install the X server or edit /etc/gdm/gdm.conf to point right place


怎么修改gdm.conf？