30 September 2011

Dell BIOS Switches

The Dell BIOS executables do have switches. Dell does not openly publish the list. There are snippets in obscure locations on their site of two of these. There maybe more switches than I have listed, and if so, please post them, or if you know what one of the switches I have not defined does, please let me know. Before I discovered there were switches, I had gone to the trouble of writing a BIOS Silent Flash script that pushed the extracted hdr file to the system.

Here is the list with definitions of the switches I have been able to define:
Switch Definition
-factory Resets the BIOS to factory settings
-forceit Forces the BIOS updates even if a laptop is not plugged into an AC power source
-forcetype Forces and BIOS file to any Dell model machine
-jabil Force the BIOS updated even though the system says it is the wrong BIOS version
-nopause Prevents the BIOS update from prompting when executing
-norburesults No remote BIOS update results (no-rbu-results)
-noreboot Prevents the PC from rebooting after the BIOS is flashed
-prgboot Most likely is used to disable windows features when flashing from a bootable DOS media
-rburesults Remote BIOS update results (rbu-results)
-reportstatus Writes a dat file containing the current installed BIOS version
-wipeall Cleans the DMI Data Area, Password, Service Tag, and Asset Tag
-wipeclean Clears the ESCD and DMI data tables. This is commonly used to resolve conflict issues and corrupted BIOS settings
-writehdrfile extracts the hdr (header) file to be flashed to the BIOS
-writehexfile extracts the hex (hexadecimal) format file to be flashed to the BIOS
-writeromfile extracts the ROM (Read Only Memory) file to be flashed to the BIOS

Command Line Execution Examples:

Used with MDT/SCCM as an application install allowing for the MDT/SCCM to reboot the machine upon completion:
T3400A11.EXE -nopause -noreboot

Writes a hdr, hex, and rom file
T3400A11.EXE -writehdrfile -writehexfile -writeromfile

Forces a BIOS update on a laptop without an AC power source
T3400A11.EXE -forceit -nopause

Creates a dat file in the same directory that contains the current installed BIOS version
T3400A11.EXE -reportstatus

NOTE: Not all of these switches work on all Dell BIOS updates executables. They vary by model. I have not confirmed these on all models, but I can tell you that the nopause, noreboot, writehdrfile, writehexfile, writeromfile, forceit, and reportstatus have worked on all 35 models that the company I work for has.


  1. Wonderful reference list; I saw -forceit and -noreboot mentioned in Dell's deployment literature, on one of the annual occasions when their website managed to load.

  2. I believe I figured out two additional switches:

    rbu stands for remote bios update

  3. Here is an update from a post I placed on Dell's enterprise forums. Dell said they do not have the information pertaining to what each of these switches mean. They said I will need to contact the BIOS makers since they are the ones that wrote the code.

  4. Do you know how to pass a BIOS password to older models? I have gx620's 745, 755, 760. The older updates dont seem to allow yo uto do it. So it I set it now, I won't be able to flash them again. For something like a 790 or e6320, it is not an issue as it can handle it fine.

    1. The firm I work for has the 745 and 755 models. I could not seem to get it to work on those either.

  5. We have a BIOS password set. Do you know how to enter this into the command line?

  6. Found here: http://en.community.dell.com/techcenter/enterprise-client/w/wiki/3461.legacy-bios-updates.aspx

    Legacy BIOS update packages do not support specifying a BIOS password when a BIOS password is already set on a system. Instead the BIOS password must be cleared using the Dell Client Configuration Toolkit (CCTK).

    To clear the BIOS password before executing the BIOS update:

    cctk.exe --setuppwd= --valsetuppwd=password

    To set the BIOS password back after executing the BIOS update:

    cctk.exe --setuppwd=password

    If a system boot password is set, then use --syspwd and --valsyspwd instead.

  7. Hi, I'm a total noob on BIOS switches but I need to extract the rom file from my HP bios exe file using the -writeromfile like u suggested above. I used the command on win 7 command prompt but it only executes the installation program. Please, guys, help me out on how I can go about using the commands listed above? So, that I can extract the bios rom file and finally flash the damn thing.

  8. Have you tried using 7-zip to see if you can extract the file?

  9. I have, but the files extracted do not have the rom executable file. Unfortunately for me, HP doesn't not offer a DOS bootable bios. All there bios is windows 7 executable and the annoying part is I can't boot(always enters a boot loop) windows on the system that's why I need to flash the bios. So any help of flashing the bios on MS DOS? I was able to boot(bootable usb) to MSDOS without any problem

  10. From my understanding, you can still extract the ROM file from the dell BIOS update file. Use 7-zip to open the file up and then extract the file starting with VL and rename it to .rom. That should get you the ROM file you are looking for.

    Do you happen to know the manufacturer of the BIOS, such as Phoenix? I rather suspect it is a Phoenix Award Bios chip. There is also a possibility that you could download a generic bios from the BIOS chip manufacturer to flash it with. Don't do this without researching first because it very well could brick your system and therefor be permanently ruined.

  11. I need the rom file for an HP bios not dell. The motherboard is insyde. Any help?

  12. Take a look at this post about extracting the ROM file from an HP bios: http://h30434.www3.hp.com/t5/Desktop-Lockups-Freezes-Hangs/How-to-Flash-BIOS-if-you-cannot-start-Windows/td-p/436381/page/2


    For older legacy Dell BIOS updaters there appears to be an undocumented switch that allows you to pass the current BIOS password. For example, I had an OptiPlex 760 and 780 and was able to use the "-p" switch to give it its current password:

    O760-A15.exe -nopause -noreboot -p=mypassword

    Hope this helps!

  14. Is there any further reading you would recommend on this?

    pneumatic switches

  15. Thanks Mick. This was a big help!


  16. I am trying to determine which BIOS chip I have on an Opti 740 minitower. Where on the mobo is that chip located ? The board is a TT708.

  17. I realize this is an older post, but I figured I should share the info. Looks like newer models (Latitude E4310 thru the newest E7x70, and OptiPlex 790 and higher) are using new command line switches, which are easily discoverable by using /? or /h with the exe. The important switches are /s for silent, and /l="C:\path with spaces\filename.txt" for logging. /r will force a reboot, but if you're doing this w/ sccm you won't want to use that switch.

  18. From my experience with the /forceit parameter, after the system has finished flashing, it will shutdown if there is no AC power supply attached. This is a bit of a pain when you have an automated BIOS distribution system.

  19. Thanks Mick , excellent post , i Bricked my T3610 , when trying to Update my bios from the files i cannot extract nothing like >T3610A18.EXE -writehdrfile -writehexfile -writeromfile on my Windows 10 , Any Advice ? Thanks Pablo