Do the BIOS updates include all updates ?

@jehoshua  BIOS updates are cumulative except for very rare cases where the release notes might say, "In order to install this update, you must already be running at least BIOS release Axx."  But again, that is VERY rare.  If you're able to install the BIOS update successfully, then it was cumulative.

@jehoshua  By the way, you can install BIOS updates outside of the OS.  Download the Windows file and put it onto a flash drive formatted as FAT32.  During startup, press F12 to access the one-time boot menu.  In there you'll find a BIOS Flash Utility.  That utility will accept the Windows BIOS update package and allow you to install it.

@jphughan- thanks I'll check it out at boot/bios level. Oh I just checked and I purchased this in July 2014, so that is a definite 'pre-2015', ..lol

With the BIOS updates, if I look at https://www.dell.com/support/home/en-au/product-support/servicetag/ and try it either entering the service tag or not entering it, there are no BIOS updates showing ??

Yet if I look at https://www.dell.com/support/home/en-au/drivers/driversdetails?driverid=k512x&oscode=1204a&productcode=inspiron-15-3542-laptop I can see the latest BIOS , plus all the previous ones.

@jehoshua  I wouldn’t worry about the year too much. I had an XPS 15 9530 from late 2013 and it supported UEFI boot, as did some even older systems. Good luck!

@jehoshua  Happy to help out!  I can't speak to level of Linux support for that system or the accuracy of that website, but if you already have this system, jump into its BIOS setup and see if you can find an option to enable UEFI boot mode.  If so, then try booting a Linux Live USB flash drive in UEFI mode and see what happens.  If you don't see an option for UEFI mode, then it's very likely a BIOS-only system, and I'm not aware of any Dell systems that originally started out as BIOS-only systems and gained support for UEFI mode as a result of a BIOS update.

@jphughan  - thanks for your replies. I can't find this Inspiron 3542 on the list at https://fwupd.org/lvfs/devices/ , so do I assume that it is NOT a "supported UEFI system (2015 onwards)" as referenced at https://www.dell.com/support/article/en-au/sln171755/update-the-dell-bios-in-a-linux-or-ubuntu-environment?lang=en#UpdateBIOS ?

Or is there a definitive list that Dell keeps, showing when this model was manufactured please ?

Yes, I checked the BIOS settings and although the boot mode is set to Legacy (I remember this was the only way to get Ubuntu going on the 3542), there is a UEFI option under boot list options. However I will keep to the 'pre 2015' instructions, just to play it safe. Thanks for your help.

I did notice with "UNetbootin" it is definitely not in the Software Centre as the Dell documents state, I had to go to https://unetbootin.github.io/linux_download.html , and perform the following commands to install it.

sudo add-apt-repository ppa:gezakovacs/ppa
sudo apt-get update
sudo apt-get install unetbootin

Had problems with using UNetbootin, basically it failed to recognise the usb drive, despite the fact it was mounted. Tried reformatting as an Ms-Dos drive and a number of other things. Noticed there are a number of outstanding bugs for UNetbootin for Ubuntu/Kubuntu.

So, found a tool to add the Bios EXE to the FreeDos ISO, then used a great tool called mkusb to create a bootable usb from that ISO. Now to reboot and update the BIOS.

mkusb is at https://help.ubuntu.com/community/mkusb

I have followed through section 3 and 4 at https://www.dell.com/support/article/en-us/sln171755/update-the-dell-bios-in-a-linux-or-ubuntu-environment?lang=en#CreatingaUSBBootableStorageDevice . Although because UNetbootin wouldn't recognise the USB drive I used mkusb to make the bootable USB.

Followed all the instructions, made the USB as #1 in the boot device priority, and then rebooted. Could see the lights going on the USB drive, however it still booted into Kubuntu, not FreeDos ??

Even if I tried the other method, the "Updating the BIOS on supported UEFI systems (2015 onwards)", when I press F12 there is no "BIOS Flash Update" option.