F6K'S DOS JOURNAL,
SECOND STEP:
BOOTING DOS FROM
A FLASH DRIVE

September 1st, 2026

Before jumping into this file's subject, I want to say that I'm 
gladly typing those words from DOS running on bare metal, using 
WordStar 7.  Actually I've wrote the last entry too from WordStar 
7, but from now on, I'll be using the version modified by Anna 
(gopher://sdf.org/users/agk).
     As a matter of fact, some days ago she released a new image 
of her usb-dos fork containing Robert J. Sawyer's own versions of 
WordStar 7 (yes, if you happen to dig in his archive released in 
his HTTP website (http://sfwriter.com/ws7.htm), you will discover 
that he is sharing, right next to the vanilla WordStar 7, various 
versions of this program modified by his own hand).  But Anna's 
copy of WordStar 7 is coming with two interesting new defaults.
     First, the program now loads properly from an other PATH 
than C:\WS (C:\APPS\WS in Anna's modified copy).  It took me a 
hard time to find out how it is to be done but in the end it can 
be changed easily; I'll point out how to do it in an other 
specific DOS journal entry where I'll talk extendedly about 
WordStar.  Second, and that's the most interesting thing to me, 
she found a way to make it default to opening from and saving to 
C:\DOCS and not from WordStar's root directory!  So the writings 
are easier to find and back up, without the need to run around 
the drives when you start the application.  I still didn't found 
out how Anna managed to make that happens but I must say it is 
very convenient and a must have--so many thanks to her!
     The disk image with Anna's copy of WordStar 7 can be found 
next to her usb-dos 0.1 fork at http://agk.sdf.org/ware/.

*

Now to our subject.  The idea here is quite simple: plug-in in a 
flash drive (most commonly an USB stick) containing a DOS 
operating system into the computer, pressing the power switch, 
and waiting 1 or 2 seconds for it to boot from the flash drive 
until it greet you with a "C:\" prompt and a blinking cursor; 
gently waiting--as the most well trained English buttler of the 
19th century--for your most silly commands.
     Well, yes.
     Better easier said than done.
     Because, if we all would love computing to be as simple as 
that, the facts show us, on a regular daily basis, that it is not 
quite the case.

     In this regard, the purpose of this file is to gather my 
notes as to provide guidance on how to achieve this result.  It 
is almost impossible for me to be exhaustive on the subject, 
given the plethora of branded machines and ways each one uses to 
achieve this.  But this file will nevertheless serve me 
personally (and will perhaps also serve to others) as a reminder 
of how one can ensure that a machine (regardless of its model) 
can be started from USB key.  In any case, and at least, to give 
some clues on how to do it.
     However, I'm not going to go into detail about how the 
system on the key should be presented (with a partition showing a 
"boot" flag, etc.) so it will actually work.  This is not the 
purpose here.
     To have a tested, proven and properly configured system on 
your USB stick, there are very good disk image files around the 
Internet which provide just that.  Please refer to my previous 
journal entry, titled "First step: installation of DOS on a flash 
drive" (DOSJ002.TXT), and/or the HTTP link to Anna's ware in the 
intro of this text file.

     So (and as Anna says) on a X86 pre-pandemic computer, to 
enter the BIOS menu, just after powering on the computer, and as 
soon as the manufacturer's logo appears, hit the key according to 
the following list:

     Acer ................... F2 or DEL 
     ASRock ................. F2 or DEL
     ASUS (desktop) ......... F2
     ASUS (motherboard) ..... F2 or DEL
     Dell ................... F2 or F12
     ECS .................... DEL
     Gigabyte ............... F2 or DEL
     HP ..................... ESC or F10
     Lenovo (desktop) ....... F1 or F2 (Fn+)
     Lenovo (ideapad) ....... F2 or F9 (Fn+)
     Lenovo (thinkpad) ...... Enter then F1
     MSI .................... DEL
     Origin PC .............. F2
     Samsung ................ F2
     Sony ................... F1, F2 or F3
     Toshiba ................ F2
     Zotac .................. DEL

     Now, I've been talking about BIOS from the beginning, but 
most recent computers don't have a BIOS but an UEFI.  No needs to 
enter into details here, suffice to know that with an UEFI, 
there's one more step to do to be able to boot the DOS system 
from the flash drive.
     If it is a BIOS or an UEFI, with the arrow keys and the 
ENTER key, navigate to the BOOT menu.  In there, set the flash 
drive (say USB key or SD Card) as the first boot device (in any 
case before the hard drive).  Additionally, if it's an UEFI 
system, still in the BOOT menu, switch the boot mode to Legacy 
Mode.
     Once that's done, go to the EXIT menu, save the changes and 
restart the computer.  With the flash drive inserted, finger 
crossed it will boot from the USB drive and, therefore, from the 
DOS system.

     Two ending notes.
     First, it can be good to know that some models have the 
option to select which device to boot from without actually 
modifying anything in the BIOS/UEFI.  For instance, on the 
machine I use, a Thinkpad X270, the boot device list is 
accessible with F12 (so just after the boot, press F12, then 
select USB and it will boot from USB).
     Second, while the BIOS access keys described above should 
work for most models, some machines are exceptions.  For 
instance, my sister's old computer is a Sony VAIO.  And on those 
models, to access the BIOS one need to press the power button 
while holding the F3 or F4 key (dependind on the VAIO).  Even 
some, like the VJZ12A Series have a completely different way of 
doing things: on those, one needs to hold the + side or the 
volume control button while powering on the computer.