Booting stops at GRUB

Was trying to something crazy on the system. Did a small change of setting the default boot to windows instead of linux on /etc/grub/grub.conf file.

Problem:
Rebooted the machine. Machine boots up after the BIOS checks, when the sytem needs to boot up from the MBR. It says the work "GRUB" and stops there.

Solution:
As i was not able to load the MBR, could not load to the single user mode. Booted up the machine using the 1st Installation disk. Followed the normal resuce mode parameters. Set the partition /boot to read/write using command
"#mount -o loop rw /dev/hdx /boot"
"#cat /etc/grub.conf" below entry shows in which drive is the MBR Loaded.
#boot=/dev/hda

ran "#grub-install /dev/hda" to reinstall the grub configuration files. It was taking a very long time, and after sometime i failed.

ran "#grub-install --recheck" This command will take quite sometime to run but finally it checks the device.map file and correct if any error. Rebooted the machine and Violaaaaaa my linux was alive and kicking...:)

Refered http://docs.redhat.com for help.