Can anyone tell me which device file is about the setting of graphic card? I can configure the
card in the GUI menu, but I'd to know which device file runing behind.

Mine one is AGP 128 Radeon. Thank you =)

It is not a device file. It is a config file. Depending what X11 (Xorg or XFree86) you are using edit either /etc/X11/xorg.conf or /etc/XF86Config. I do not recommend using GUI programs to edit config files unless you like pulling your hair out all day and you do not mind creating backups before using the config programs. Editing config files by hand is a lot easier than figuring out the problems that GUI programs screwd up on.

BTW, double posting is against the rules.

First of all, thank you for the reply and I like to state that I know well about the rules of this forum. There just a little technical problem on submitting the thread which make me double post.

And there are always post suggesting on how to seek for help, write a clear and relevant subject........ I found this forum is quite helpful, a nice place for people around the world interested in Linux and I would like to contribute to the discussion if I able to.

I set something wrong on my graphic card so when I boot up the machine, I can still see lit of service entry start up [ok], after that I see nothing like the login page.

How can I bootup the machine, list the files in hdd and re-edit the XFree86 config file manually?

Thank you for kindly help again.

Can you SSH to the machine? Try to get into it with SSH and go into the file. As always, back stuff up before "messing with it." Maybe?

I found your thread because I am looking for an answer to my question:
Can I remove the "Section 'Screen'" lines in order to see the GUI on startup?

I can not login the machine so I can not ssh to the account.

After edit the parameter in the bootloader and login through text mode (level 3), the problem is solved. Thank you for help