when you turn on the computer, the power-on self-test (post) performs a series of tests to check the operation of system components and some of the installed options.

    if post finishes without detecting any problems, the first window of your operating system or application program opens.

    if post detects a problem, more than one beep sounds and an error message appears on the screen.

    1. if you have set a user password, you must type the password and press enter, when prompted, before the operating system will start.

    2. a single problem might cause several error messages. when this occurs, work to correct the cause of the first error message. after you correct the cause of the first error message, the other error messages usually will be resolved the next time you run the test.