Linux - Enter into Single User Mode in GRUB

1 .During the boot stage - GRUB, sleect the corresponding kernal
2. press [e]
root (hd0,0)
kernel /boot/vmlinuz-2.4.19 root=/dev/hda1
3. edit as follows:
root (hd0,0)
kernel /boot/vmlinuz-2.4.19 root=/dev/hda1 single
4. press [Enter] > [b]