Abstract: A method for suspending and resuming a computer system without being affected by an abnormal power failure. The relevant operating information and context of the related devices are stored in both a memory and a hard disk before the computer system enters into a sleep state. If a power failure occurs, relevant operating information of the system can still be fetched from the hard disk to restore the computer system to its original operating state even though the information saved in the memory is lost. Also, the computer system can self turn on and activate a “wake on LAN” function and a “ring in wake up” function when power resumes after a sudden power failure before entering into the soft-off state. Therefore, users and system administrator can wake up the computer system from a remote site in a very convenient way.