if i give the command gdm-safe-restart means it shows that "Can't find the PID file in the configuration file, going to try: /var/run/gdm.pid /var/run/gdm.pid dosen't exist, perhaps GDM isn't running " lisk this i got now what i have to do...
... you said you had accidentally deleted the root user.
The error message "the GDM user 'gdm' does not exist.Please correct GDM configuration..." indicates you had deleted the "gdm" user too. If you have a backup that includes /etc/passwd and /etc/shadow, please restore those files.
What *exactly* did you do when the problem appeared? Exact commands would be good to know, to estimate the extent of damage they caused to your system.
What is the name and version of your Linux distribution? (RedHat Enterprise Linux, RedHat Linux, SuSE, Debian, Ubuntu, other?)
The procedure to restart gdm (after you've restored the missing user ID) depends on the Linux distribution. You might want to try these commands:
