EEPROM BIOS Firmware flashing, the good , the bad and the ugly.   
Or how to Brick a PC easy?

Most folks that do this end up bricking their PC; see 10 reasons why here.

Best practice is leave it alone! (lacking skills and experience) OMG OEMs are now doing auto BIOS-UEFI updates !)
Why brick a good PC that ran say for 5 years perfectly?( reading FUD? on line?)

This job is to upgrade your BIOS Firmware,  located in EEPROM flash memory. (8pin device)
The word flashing is a verb, the act of burning the EEPROM with new BIOS machine code.
This firmware has 100 year retention factor and does not just leak out by accident!
See my super short list (modern PCs)
A Dell PC burn.

The  BIOS ROM history in a nut shell: (note how the first 3 can not ever get infected, pure hardware logic rules)
  • 1981 IBM PC (it used a ROM) soldered to the motherboard. (no way to update this pig it can not be re-programmed or reburned it is only ROM!)
  • Then PC clones were born  and  used  UV erased,  EPROM(in sockets if lucky and you remove it and burn it in  EPROM programmer)
  • Then came 1995 EEPROM (electrically alterable/ & erased), with a nice and handy, (write protect WP jumper making virus infections IMPOSSIBLE ! )
  • Next ~ 2000 ,the asinine PC makers removed the loved WP  Jumper clip and now any BIOS can become infected, (in theory , in practice super hard and RARE as H3LL)
  • Fast forward to 2020 and CLASS 3 level UEFI. (see my rant)
Do not confuse jumper WP "write protect" with (Password reset or CLR_PW, or CLR_CMOS or alternate BIOS mode jumpers ) WP was deleted at near 2013 year.
WP lasted for 15 years, 1995  to 2010. ( gone now for a savings of 2 whole cents)  Even longer with EPROM 1981 up.
  ast seen Via NAB7500 (2007) &ThinkPad x131e(2013)Gigabyte GA-8i91me, or Foxconn NF4K8mc. ABIT VA-20 , & endless lists.
The Foxconn manual even stated as "to prevent BIOS virus infections" in clear English, what happened? now?
They lost (DELETED) the 1cent jumper.  ( to save  a penny on a jumper , give me a break, how inane could they get?)

Also loved and now missing is the EEPROM socket, or worse the SMD chips that have only bottom side pins that can never be touched.
With socket I can move my EEPROM to a programmer and backup the firmware easy.  ( but this is now gone )
The OEM makers of PC also removed the the burning APP's  exe, switch (parameter CLI) to backup the firmware,  NO GONE,  OEM's hate backups now,  amazing no?

The most safe ways to burn any EPROM is not using nasty infected Windows.
There were 3 ways, historically,  FreeDOS/LINUX or BIOS current burns new BIOS.
Some OEMs (most) ban all that now, and use Windows cold reboots to run a Windows virtual DOS (and not documented)
The OEM's makers then make the EXE file encrypted to you can not unpack it and see the EXE the scripts or binary.rom file nor the burn scripts.
There is no point here to show how to burn your EEPROM  firmware BIOS.
It is a vast moving set of rules now , ending at what UEFI allows or  not. ( Ask your OEM for help, or avoid all this and leave BIOS alone)

Get your BIOS from (as appropriate) ,,, , ,etc)
The if you must update your BIOS, using , the correct files from above matching your country , your exact PC model and better the serial number or you will suffer #1 failures below!
I first backup  or  hand record all my BIOS setting not the same as DEFAULT ( know your BIOS first, then flash it)
After any update or new CMOS battery , make sure time and date are correct in BIOS and PXE off, and boot order HDD0/SSD0 is top of list.
Flash, burn or update EEPROM main firmware.

Pitfalls: ( I expanded on the 10 ways to fail here)
The PC must  pass Diagnostics first, ask your PC maker for those, or if DELL  power on hammer F12 , lcick ePSA diagnostics,  rule to all batteries must be good  and or  charged.
Do not burn with a CMOS battery is dead or weak, at 5-7 years old.
  1. Using the wrong BIOS Binary image files will brick any PC easy  (ask your OEM maker to give you a perfect PC and OS match on Firmware) Gee even matching your PCs exact serial number (yah think?)
  2. Failure to use a UPS  to keep AC power from dropping dead or glitching or power surges/bumps or brownouts, mid burn and flashing the EEPROM. (or during a lightening storm.?)
  3. Do not flash PCs that have power   problems or dead/weak batteries
  4. Do not flash any overheating PC, or about too overheat  or loves to do so, fail you will.
  5. If allowed use this MSDOS  boot method to burn BIOS.
  6. Just as good , as DOS is  EZ-FLASH  if allowed and provide in your Current BIOS update page. (look for this and use it if  present) I  call this a  resident burn)
  7. Flashing under WINDOWS  is silly, after all it may be infected, or corrupted, and see everyone bricking there PC here?  BIOS update  bricks 8 million.   or    Windows update bricks 168++ million  ?
  8. Flashing for fun  ( If the PC runs perfectly why do this? or worse you bricked a perfectly good PC.) (I now see crazy OEM doing Auto BIOS updates,  you are doomed and if not now SOON)
  9. Flashing any PC that is overclocked (Gamers toy PC's, etc...)) DOOMED TO FAIL.
  10. Flashing from any bad/weak  HDD  or fails PC Hardware diagnosics.
  11. Kids (or goats, cat/dog) playing near you  and tripping on or eating on power cords? While BURNING. see #2
  12. The new PCs that are 100% UEFI only PCs  can not no longer burn with FreeDos, linux CLI or EZ Flash.
  13. Watch out for any PC that has old GPU card (Desktops) that UEFI does not allow now,. Class3 UEFI.
  14. Watch out if using USB boots to load burn BIOS, if USB3 ports may be dead  on  first PCs made with USB3, so use USB2 ports.
  15. You formatted the USB  boot and burn memory stick using the wrong format,  FAT32 is best most times. (applies to hand made USB with  ROM burning kit placed on it only)
  16. The ROM binary file(s) downloaded is corrupted, and you forgot to MD5 checksum the file for clean download.
  17. The act of , jumping from too old BIOS to the newest UEFI ( you failed to read the text files , that told you this update can not be regresssed.)  Best is do not allow this update to run. (one way trips can brick the PC)
  18. Make sure the PC runs ok in genernal and cold booted has no Passwords of any kind  before windows loads.
  19. Make sure PC boots in the correct order,  in BIOS, HDD0, USB, CD.
  20. Before updating the BIOS, ensure that you suspend BitLocker encryption on a BitLocker-enabled system.!
  21. The BIOS with Admin BIOS Passwords enable can fail. turn it off before the burn.
  22. Remember that on new PCs, you only get 1 file from the OEM and  xyz123update.exe,   you run that and PC cold boots and burns the EEPROM firmware update and you get no control at all and no way to backup old.

Some good reasons to flash BIOS?  (sorry not by the phases of the moon)
  • To gain support for newer and faster CPU  or more cores in your processor. (mostly on gaming PCs or high end enterprise PCs)
  • To gain support for newer and higher density or larger , DDR RAM.
  • To fix a specific bug in your BIOS that only you have now, right now, or the newer revision makes USB3 work even under BIOS. (learn that most bugs you will not experience in a life time so read carefully)
  • To make UEFI work right, some PCs have 20 upgrades , for UEFI too  and for versions Class 1, 2, and last 3,  avoid 3 if wise and or just hate bricked PC's.
Below is my expanded list of how to fail, (I'm the guy that had to fix the dead PC after others messed it up....(flash began about 1995 , before that was UV  erased EPROMs) Did them all vast times. (have bench programmer too)

Top ways to brick any PC
Flashing and burning new firmware
  • PC fails diagnostics or any or all batteries dead at 5 years old.
  • Wrong BIOS update files (apps) not from your OEM support pages, or for the wrong model. PC.
  • AC power loss at the burn or  in a lightning storm, or power surges all day long, (just don't  let this happen)

The best ways to flash, are:  (after any OEM method fails try this, the old fashioned safe way)

  • Use Ez-flash BIOS. (this is BIOS that flashes it  self , seems contradictory, but is not)
  • Use FREEDOS  (a very safe way for sure)
  • Use The OEM's makers most safe methods. (ask them but just the OEM  and  watch out for young inexperienced and caviler geeks telling you wrong. )
  • Never use WINDOWS to flash, or you will brick the PC. ( some use a PREBOOT WINDOWS environment that is safer but tell me how this works on 5 year old infected PC, tell me , I'm all ears?)
  • Never flash using the HDD if the HDD fails SMART tests, this is DOOM city.
Do not take risks and flash without making 100% sure your binary files (newbios.bin) matches your exact PC model and submodel or even your country. (and all sub model numbers or even your serial number)

Here is me flashing and HP computer, using the HP Freedos way  (if the PC lacks EZ-flash) The modern PC the BIOS can find a rom.bin file and is not simple like EZ_flash, at all.
HP  ERomqap utility FLASH! If the below fails, this works 2nd best.

On a older  HP with odd non friendly EZ_flash  (now gone on all NEW OEM PC's with UEFI)
  1. Your PC is dead (worst case) and you go to PC #2 any PC good (windows), and go to and download your exact matching SP12345.exe file (fake nnnnn here) Do not get the wrong file !!!
  2. Put the file on a USB stick fat32 formatted first, and then with 7zip (free) extract the SP12345.exe into its full set of uncompressed files. (it will be a non bootable USB ok? just files there) In 7Zip right click Extract HERE
  3. (one modern example is)Rename USB file, the 018A4.FD file to 018A4.BIN and save it to the root of the usb flash drive. (this is a very critical step, using the correct 8.3 extension name)
  4. Remove USB stick from good PC2 and move it to dead PC1. (this fools many this step) we called it sneaker net for year. sneaking from PC2 to PC1.  (for sure network drivers DEAD)
  5. On the target PC1 make sure PC is in legacy mode or UEFI turned off, as this is all trouble you do not want.
  6. Press the notebook's power button and immediately hold down the Windows key and the B key until the notebook reacts and begins the BIOS recovery.  (this is the LAME HP EZ_flash way, and not so easy is it)

  7. Cross fingers, and it works for me .
The SP12345.exe file must  match the whole PC model and sub model numbers,  like my  HP8540w- 12345ABA# if not YOU  WILL BRICK THE PC OK? 
Many HP with same simple model names, have like 10 motherboards used world wide, even with AMD chips not INTEL and if you get the wrong file you will brick this easy as falling off a log.
Best of all is using  support page and tell HP what serial number your PC is from the F1 BIOS information page.
If WinKey +B fails , HP does not support this method now (win +B is go back to older BIOS)

See DELL's EZ burn here.
Pure love here, when see, as we know this engine here is NOT infected so the burn will work every time, I have done so countless times.
The Dell and Asus screens are super simple to see and understand, why HP makes this sow weird IDK.
EZ-Flash real or by any other name, is best if found. (the only trick is how the USB stick is formatted, Fat16/32/NTFS (ask the OEM this first)  No need for any HDD at all, and can be far safer leaving it out.
Here is Ez-flash ( yes, the best way if present)  done with ZERO BOOT DEVICE MEDIA, but use a USB stick for only the  flash.bin file.   P5Q-ws~1.ROM   best is to use 8.3 file names , ok?

This runs in Intel CPU "REAL" mode, and is 100% safe, the most safe way on earth to flash is with EZ-flash.
First  make sure you backed up your old BIOS  or download say the top 10 versions just in case.  (have a regression path planned out )
Most OEM's have very horrible documentation on BIOS (no books) and for sure the details of each BIOS change, ( like stating only change was , CPU  microcode updates, gee why not tell what was done or added.?)
See my UEFI rant here.

More FREEDOS examples.  ( I like having one powerful FREEDOS boot USB stick that can run any BURN UTILITY made.)   With full memory manager loaded.
I use the same way to burn new firmware on all my LSI 93xx  RAID cards,  easy as pie , use full version of FreeDSO only. not light.(lite)
HP  Elitebook 8540w actual, just before the burn.

I always look for a way to backup Firmware first. My  version of Eprompaq has  no  buckup mode at all, sadly.
Some OEM's fear that Backup.rom files (bu.bin) will then be edited  and infected then be sent out on the web,  like at  ,  free firmware site (fake, example)
The do not allow this now using THIER tools.

Each PC maker has there own way to flash the BIOS. (some are good others are vary risky some offer 3 ways to do this with not one warning on true and accurate risk levels)
From best to worse here they are:
  1. EZ-FLASH (or by any othername) is BIOS code in the protected blocks burning the other firmware blocks, the actual upgrade to BIOS or UEFI.
  2. FREEDOS (or MSDOS6.2x) Free is best as it is free.
  3. Windows preboot environment where multitasking is turned  off , is safe but if Windows is corrupted, sorry NO JOY.  ( be sure to run the program with /r  switch set)
  4. Burning from Windows Desktop is doom city,  like walking across the street blind folded,  what a 50 /50 chance?  BUT AS WE ALL KNOW LUCK HAPPENS , and can REPEAT.
  5. Yes some older odd duck PC burn BIOS in a bootable LINUX no GUI mode, and mulitasking disabled. (from CD or from USB stick)
Closely related to this is the GPU card now goes dead using say safe wonderful FREEDOS. (See links that below) Some Video cards (2014 UEFI  lame cards) will not allow VESA int10h mode 103h 800x600 {256color}

The best way for PC makers to handle this is to have EZ-flash so there is no need for MSDOS(Freedos) with 100% class 3 UEFI rated cards or PCs'  Class 3 is insane crazy strict UEFI(BIOS) UEFI is a wrapper around BIOS in most cases. CMS is best of all only buy PC with CMS options in BIOS and WIN .

Flashing means or burning, is  to charge up the EEPROM cells gates.  A.K.A. programming or burning and  in the very old days' fusing the PROM's)  EE = electrically erasable and alterable.
This gate is like a very tiny capacitor that charged up with electrons. This is how 1 binary bit is stored,
This chip does not forget or leak bits to the bytebucket at all. 100+ year  retention spec.
Flashing is the ACT of charging the GATES of this transistor (millions of them)
The term Flash was used when EEPROM started at  Intel or SEEQ. (old EEPROM were slow,so they  learned how to make them  faster  and coind the word FLASH . (10mS per byte or less is FAST)
The FLASH simply charges up the MOS floating gates. (after erasure)  this is just ONE BIT CELL. (1 of 8 million on mine)
This cell charge can LAST  for 200 years. (from top makers like Microchip(tm) "data retention spec. shows 200 years." 
They have oxide layer under the gate that is super impurity free !  ( mostly job#1 on all CMOS made) this! If  made correctly life span is 100 years, holding data on  the floating gate that long.!
Below is  a typical EEPROM CHIP with 8 pins (large) and Surface Mounted Device or  SMD, used today, and has no socket. (sadly) 
25Q16 is 16 Million BITS Q25 IS  512 million bits. (modern serial EPROMs called SPI) The "Microchip AT24CM02" is linked below)

Citations , in all cases use my links to maker  (page 21, write cycle timing, if an  "ACK" is missed, or the programming pulse is too short or missing called Twr, at 10mS minimum ,not using ACK method) FAILS:
262K Bytes Serial EEPROM 2‑Mbit (262,144 x 8)
If you learn how EEPROM work even basic basics, you will learn fast that TIMING must be CORRECT or you brick the burn and PC. (and any multitasking OS can cause bad TIMING, SUPER EASY and fail)
The modern chips do not need to be pre Erased  before the burn (magic inside?) (it auto erases as you program it, like magic)

An Example BURN:  A DELL PC)  NO better way exists on planet earth than F12 BURN / Flashed updates)
This is only to show that  Dell Flash updates do not just  do one EEprom main update, it does 3+ in a row. Logged proof here.
The Dell PC with
Dell Support Assistant software ,  does this burn automatically with out your permisssion, DO NOT RUN this DELL Assistant. (or learn how to defeat this crazy idea)

1.4.5 INSTALLED (Dell System OptiPlex 7040)
– Gigabit Ethernet : 0.8
– Intel Management Engine (VPro) Update :
– System BIOS with BIOS Guard  : 1.4.5
1.5.4 UPDATE ( OptiPlex 7040)
– System BIOS with BIOS Guard  : 1.5.4
– Gigabit Ethernet : 0.8
– Intel Management Engine (VPro) Update :
– System Map : 1.0.1
– PCR0 XML :

Exit Code = 2 (Reboot Required)

below are are all ways to burn that are unsafe in RED.

The above BIOS FLASH UPDATE/ F12 I call EZflash, with any UPS . $100 device.  (200watts will run most PCs lacking GTX690 300watt GPU card)
Flashing pure in Windows with Desktop running, is recipe  for disaster.
Dells (for example) Windows flash methods are not disclosed, and the EXE binary can not be unzipped.  ALL a bloody secret. (but I am sure if your windows is infected you are doomed doing it this way)

Let me be more clear, for decades I first backed up the onboard, BIOS, to file then burned the EEPROM with new firmware, if that failed,  I can go back to the one I just backed up,  They now do not let me do that, (the bums)
This nasy fact means bricking a good $350 Motherboard is too easy.
The reasons all this is so hard will be told here, I will tell all pitfalls here. 
The #1 reason to fail is timing to flash any EEPROM (firmware) the timing must not be wrong, and windows loves to get this wrong.
The 2nd PITFALL is using the wrong, BIOS xyz123.exe file (the ROM file we call this) take my Dell 3020 MT, and is not at all a Dell 3020M (means micro) they are NOT THE SAME PC, nor the same BIOS at all. Not by a country mile.
Pitfall #3 us make sure burn file is 8.3 filename rules just in case. (12345678.exe , not "Dell Optiplex-790mt.exe" ok? See goodones below.
  • Any empty USB memory stick any size is ok even relics. "a.k.a. Thumb drive, or Udisk, means USB memory disk.(stick)
  • Formatted to FAT32,  never use FAT16 from the DOS days , ok  that is a general statement, for TODAY. (not 1985)
  • Create NO PARTITIONS ON THIS STICK. just 1 file.
  • Then copy the CORRECT file from DELL to the Stick.  mine is O3020mt.exe (not O2030m.exe on mine ever)  DO NOT BURN PC's guessing wrong file for PC.
  • Power on hit F2 and turn off bitlocker, I even go 1 step more and remove the boot drive, (or all Drives, via simple cable pull (DT, example desktop)
  • In F2 , turn off UEFI secure boot  if on and turn off TPM, and turn off PXE booting (a silly dell defualt this turn it off now) PXE is server Thin-net booting you do not have at home.
  • Step 6 below is age  old , and should say, F12 actually does the BURN here, there is no DOS, in fact you get a F12 window that does the actual burn.
  • Burn (or call it flashing) not the highest version on the list, at DELL try the next one above your first. then if that works move higher,  in say 4 version steps,  (if fail go smaller steps, ok)
One more thing that may be needed too, is ture off SAFE BOOT in BIOS.(F2)
Keep in mind, some or ALL UEFI  PCs DO NOT allow a regression path for BIOS,  once UEFI is Class 2.x up,  you are stuck there. (not legacy but no regression of BIOS)
The Older DELLS pre 2010 , have no F12 UPDATE BIOS feature. (the cure for that is DDDP, Dells very own DOS..)
DDDP is not corrupted, it is fresh and is not multitasking, so Flash timings are not WRONG. DDDP is very very good.  (vastly better than Windows)

At version UEFI Class 3 (iii) there is no more legacy at all,  and the OS is married to the mobo and GPU card  and is now an intractable POS  . (UEFI stinks page)

The future is daily  automatic BIOS upgrades (I never allow this) and  your $350 MoBo is now bricked hard. (Not my beloved Asus z270 prime)

The Dell rules are here, and not too good (due to evolved changes), but does work. (F12) Note how it skips step #0 ,dang.

Better for home users is the 2012 AND NEWER, DELL PCs with F12 burn, as seen below.  DO THIS FIRST , if F12 BIOS FLASH UPDATE IS THERE ?
Power on the PC and quickly (at dell logo) hammer F12 key, (no dead wireless battery keyboards need apply)
This  is DELL's version of EZ-FLASH./BURN as seen here.
Dells  EZ BURN like:! F12 it's Dell name and hot key. Nothing could be safer.
NIC = network interface card, or in my case is the Ethernet and PXE boot DISABLED for thin-net boot servers nobody has at home.  (the M.2 is a SSD gum stick boot drive)

end Dell burn.

CSM = Compatibility Support Module, or Dual BIOS, or legacy + UEFI mode. (the best is here)<<< means you still have some control.
BIOS = BASIC Input Output System, or FIRMWARE the only intelligence in the PC with all boot media removed;
UEFI is BIOS in a wrapper.@ Class 3, kills: regression,  << UEFI rant.
RTM = Read the manual at your OEM makers website
OEM = Origional Equipment Manufacture. (eg:. and,, ,etc  )
Burning or Flashing (verb) the act of reprogramming the Firmware. (by any means) or BIOS/UEFI UPDATES
DOS, I mean Freedos, a great OS that is virus free, and is single tasking OS that burns with clean accurate clocks and does not weak the burn ever.
EEprom =
electrically erasable programmable read-only memory   (reads fast , programs slow) and has erase mode, some even have autoerase. ROM are not used, nor are EPROMs for decades now.

Freedos (16bit still) is a new version of DOS and  is not allowed at all now with UEFI, so no more safe, BIOS burns with DOS. (infected windows burns now)
Dells  DOS called DDDP, does work correctly. (and easy to use)(and used for years is now gone.
ROM files the BIOS files called update123.bin or dot ROM are now gone  and  made illegal now by UEFI.
USB STICK or STICK means USB memory , fob/key/thumb drive, or Udisk.
BRICKED means the PC is now 100% dead  as is the BIOS or UEFI and in many cases can not be regressed or recovered at all.  (so stop flashing BIOS and win?)  or will not boot any media of any kind is bricked.

My best PC, (CSM joy) is Z370 Prime

Below is my first Intel 1702 EPROM with a quarz UV light windows. The bonding wires are seen clearly. See the die, see the array of floating gate MOS.

My UEFI  RANT,  (short and sweet?) . ( this my opinion only)
    We love BIOS and hate UEFI.

    Version-#7  5-9-2017   (v1)    v7=Sept-2021 , more UEFI warnings. and pitfalls.