If GRUB was not installed during the installation process, it
can be installed afterward. Once installed, it automatically
becomes the default boot loader.
Before installing GRUB, make sure to use the latest GRUB package
available or use the GRUB package from the installation CD-ROMs.
For instructions on installing packages, refer to the chapter
titled Package Management with RPM in the
Red Hat Enterprise Linux System Administration
Once the GRUB package is installed, open a root shell prompt and
run the command /sbin/grub-install <location>, where <location> is the location that the GRUB
Stage 1 boot loader should be installed. For example, the following
command installs GRUB to the MBR of the master IDE device on the
primary IDE bus:
The next time the system boots, the GRUB graphical boot loader
menu appears before the kernel loads into memory.