This article is from the the Brief Linux FAQ (BLFAQ) Maintained by Neil Zanella nzanella@ganymede.cs.mun.ca
If you are running Red Hat then you can edit the file /etc/inittab on your system and replace the entry
id:3:initdefault:
with the entry
id:5:initdefault:
and reboot. On other systems you might have to change the number 5 (the run level) to another number like 4. How to choose the correct run level should be clear by reading the comments in the file /etc/inittab . Alternatively, you might have to change a link in /etc/rc[2345].d . Run levels 2-5 don't have really strong conventions behind them like 0, 1, and 6 do. It depends on the distribution.
 
Continue to: