Dell error code 2000-0142, which often reads as "Self-test Unsuccessful" or "Drive Self-Test Failed," means a problem exists with the system's hard drive. Specifically, when conducting a diagnostic self-test, the hard disk drive encountered a failure and it requires corrective action. The error is accompanied by a "beep code" of one-four-two and sometimes preceded by a Blue Screen of Death, which indicates a failure causing a complete system shutdown.
When encountering the 2000-0142 error code, Dell technical support recommends several steps to handle the problem. First, they recommend updating to the latest system BIOS, meaning basic input-output system. This is the program a microprocessor utilizes to initiate computer processes after a machine is powered on. The BIOS also handles data transmission between the operating system and any attached devices, such as a mouse, printer, keyboard and hard disk. Instructions for BIOS updates vary by manufacturer and should be followed cautiously.
Second, Dell advises shutting down the computer and removing all possible power sources, such as a battery, AC adapter or desktop power cord. Next step is to disconnect the hard disk drive from the system board and then reconnect it. After that, re-attach all necessary power sources.
Finally, after those steps are complete, Dell recommends running a repeat diagnostic test to determine whether or not the problem related to error code 2000-0142 has been resolved.