[问题]xorg.conf is invalid or doesn't exist

[xsoul]

I installed the 9755 nvidia driver (graphic card GForce MX400), then restarted, arrived in a black screen saying something like the driver and the graphic card don't match. then I uninstalled the driver, restarted, got this result:
I checked the filesystem-etc-X11, the xorg.conf is gone. Is the backup file created(/var/backups/xorg/xorg.conf.2007-06-14-00:05:40) when I install the 9755 driver useful to correct this? If so/not, how?
forgive me for typing english

[chaoyagami]

please 讲中国话，我看不懂英文。

[raojunscu]

仔细找照/etc/X11/下的文件 应该有备份的 以～或者其他结尾的

[xsoul]

I can't find the backup under /etc/X11/.
but I've found one under /var/backups/. I tried to copy it to /etc/X11/, but didn't work, says I didn't have the permission to change files in /etc/X11/.