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 appears.

    if post detects a problem, more than one beep might sound, an error message might appear on your screen, or both.

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

    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 typically will resolve the next time you run the test.