Legacy Guide
This Guide is for hardware manufactured before 2010 which has now reached end of support. For newer systems (~2010 or later) the diagnostics are all incorporated into the UEFI BIOS (or late Legacy BIOS) of the motherboard for more details see here. For older systems (~ before 2010) the extended diagnostics were contained on a diagnostics partition on the hard drive which could be removed during manual installation or inaccessible if the hard drive failed thus it is recommended to make a diagnostics bootable USB or CD.
Older Systems
Note many older systems had a diagnostics partition on the hard drive, however by now this partition has likely been removed by reinstallation of the Operating System. Also if the hard drive is damaged the extended tests will also be unable to run. In such a case you will get an error message saying the system can’t boot to the diagnostics utility. These extended tests can instead be run off a CD or a USB (this USB must be <2 GB and really old systems before 2006 won’t boot from a USB).
To run the diagnostics on such systems please download the following file (on a working system) A1394A0. Run the .exe

Extract to the default location

Once the files extract navigate to this folder and run the DDDP program (if it doesn’t automatically run)

The DDDP program will now run

Select Create a Bootable CD or Install to a USB Flash Drive. The CD/DVD is usually more reliable.
Once you have made the diagnostics CD/DVD or USB stick insert the CD/DVD or plug the USB stick into your problem system.
Power down your computer if not already powered down and wait at least 10 seconds before powering it back up. Hold F12 while powering up your computer (at the Dell BIOS screen).

Select boot from CD/DVD or from USB respectively.
Run the extended diagnostics and tests.
Error Codes
The most common are:
- 2000-0142 – the HDD/SSD has failed
- 2000-0146 – the HDD/SSD has failed
- 2000-0123 – the RAM has failed
You can reseat these and then try again in case the cables/connections are loose. If you have another error code confer with the Reference Table of ePSA, PSA Error Codes and Troubleshooting Steps.
The Drive and Memory Modules are the parts most likely to fail however they are fortunately usually also the easiest to replace. Your can purchase a Solid State Drive or Replacement Memory Modules from Crucial using my affiliate link below. More details about looking for compatible parts and finding your Service Manual are available below:
Older Systems – Recreating the Diagnostics Partition
Personally I don't recreate the diagnostics partition on such systems as I find the HDD the most likely component to fail. Relying on diagnostics installed on a failed component is a bit of a chicken and egg situation.
The only way I found to create the diagnostics partition is from a Media Direct DVD. For more details see Preparing your Hard Drive: Setting Up Media Direct on Dell Systems.
If your system is not a Media Direct system you can delete Disk 0 Partition 2 and Disk 0 Partition 3: MEDIADIRECT during Windows OS installation and recreate a new partition to reclaim the 2 GB of space. I have tested this procedure on a Latitude D820, OptiPlex 745, 755 and 760 which all aren't Media Direct systems.

Does this software works on 32/64bit wind 8.1 aswell?Got dell precession 380 tower trying to access
f12 menu but cant nothing happens blank screen.
If diagnostics media is made its bootable within the Legacy BIOS otherwise some of the diagnostic tests are inbuilt into the BIOS.
If you cannot press F12, hold down the power button for 30 s and then remove the AC cable. Then plug it back in and power up and tap F12 repeatedly. Use a Dell wired keyboard if possible.
my laptoop is preparing automatic repair and some secand after diognosing your pc but not start laptoop place help
Hold down the power button for 30 seconds then follow the instructions to power up and press F12…
I was doing a factory reset on my dell inspiron 14 and before it finished it crashed. now i cannot enter my desktop because it will neither let me repair or reinstal from F12 BIOS reboot. Can you help
I forgot my HDD password and I can't get into my computer
Follow the instructions here to recover your files:
http://dellwindowsreinstallationguide.com/data-recovery-using-fedora/
My laptop is preparing automatic repair and some seconds, after diognosing your Pc and start over again. please help
What make and model of laptop? Have the preboot diagnostics passed or failed?
I have tried everything. I dont know if my son completely wiped out the computer but when i turn it on it goes to Processing Reortation. You click the green to agree and the Error 1 pops up. I have pics that i can send to you. How do i get this computer to work. Its a Dell Latitude D630
Hi,
I'm using dell mini inspiron 1012 laptop.. While booting it shows pxe-e61,pxe-m0f,os not found msg is shown on a block screen I tried a lot pls help me to come over from it…..
Hi,
I'm using dell mini inspiron laptop.. While booting it shows pxe-e61,pxe-m0f,os not found msg is shown on a block screen I tried a lot old help me to come over from it…..
PXE-E61: Media test failure, check cable
PXE-M0F: Exiting Broadcom PXE ROM
Operating system not found.
From others on the forums. First check there is nothing in the card reader. Then try to power up as normal.
If it still displays. Power up your Dell and press [ F12 ] does your Hard Drive display on the boot menu?