System installation RHEL5.1, at first the device can not recognize the hard disk, after viewing the BIOS settings because the hard drive interface mode is adjusted after PATA SATA interface mode, you can enter into the system boot interface.
And when the system starts each service, because one of the service failure can not enter the system.
Using optical discs into the Linux Rescue Mode, chroot / mnt / sysimage
chkconfig - list to view the boot service, the system comes with all the normal service
Some of the services path preceded by the # cat /etc/rc.local before the set commented, after the restart given service does not appear, the system enters normal
Forgot your password, change the root password
Linux Rescue CD mode (omitted here ..) enter the command passwd, modify the new password prompt, secondary confirmation after modification.
The system with the new password to enter, succeed.
Note: where the Linux hard drive mounted under Windows systems for data backup, use the tool to see Linux reader to Linux partitions from the disk, the data can be backed up.