This article, which focuses on the BIOS settings you might need to configure before you install Debian, is part of a series dedicated to this Linux distribution:
- The pre-installation process – Reviewing your BIOS settings before doing the installation (YOU ARE HERE)
If you are already familiar with some of these steps, you can skip ahead to the part more suited to your needs. Otherwise, keep on reading!
When it comes to installing a new operating system on a computer, reviewing its UEFI settings is an often-forgotten but crucial part of the process.
Doing so will ensure that you won’t encounter any compatibility issues when installing Debian on your laptop or desktop computer. A failure to modify some UEFI settings accordingly will prevent you from adequately launching the Debian installer.
Not everyone will need to make adjustments to their BIOS parameters. For instance, those switching from a different Linux distribution will not have to modify anything. However, if you are coming from Windows 10, you will be glad to have everything set before starting the installation process.
The main reason for checking out your BIOS settings is that it might have a boot order that prioritizes your hard drive. That, in turn, will make it so that even with the pen drive inserted, the computer will bypass the Debian installer upon restarting and go straight to the hard drive OS.


To avoid this, you should ensure that the UEFI boot order prioritizes booting from USB first before booting from the hard drive. With that setting implemented, your computer will first check to see whether an inserted USB flash drive contains an OS installer upon starting up. If so, it will boot it. If no pen drive is present, or if it contains no bootable disc image, it will then skip to the drive indicated as priority number two. That should be your internal hard drive.
The other reason for the BIOS changes is that some machines have a fast boot setting. This parameter can be problematic. The fast boot results in a partial suspension of the disk, which means that you get a computer that starts up faster. However, it also means that your computer doesn’t do a full reboot of the system when you “shut it down.”


The Windows 10 fast boot setting in itself isn’t incompatible with Debian. However, it might result in the start-up sequence being so short that you will automatically boot into Windows 10 before having the opportunity to install your Linux distribution. As such, you will have problems triggering the Debian install when you start your laptop or computer. That is why you must disable the Windows 10 fast boot setting before installing Debian.
Another reason that Debian recommends reviewing your BIOS settings is that all modern computers use UEFI, a more modern alternative to BIOS.
Lastly, even though we still use the word BIOS, most if not all computers and laptops bought these past couple years use UEFI (“Unified Extensible Firmware Interface”). That firmware comes with a setting called secure boot, which is a great feature…Until you need to install Linux. More often than not, the only boot code accepted on UEFI firmware when secure boot is activated is the one provided by Microsoft. That means that if your UEFI has secure boot enabled by default, you won’t be able to boot the Debian installer. Note that if you own the 64-bit version of Windows 10, I can virtually guarantee that your secure boot is activated.
Unfortunately, there is no standard procedure when it comes to modifying your UEFI settings. Changing the boot order priority, deactivating the secure boot feature, and disabling the fast boot setting are processes that will vary according to your UEFI version. As such, the procedure will depend on your computer model.
Please refer to this ITgirl.tech article for an in-depth tutorial on how to change your UEFI settings. In it, you will find a step-by-step guide with screenshots (for all major computer brands) to do the following:
1. Set your USB peripheral as the highest priority in the boot order
2. Disable fast boot (if applicable)
3. Disable your secure boot setting (if applicable)
Now that we have reviewed the BIOS settings, you can start reading the last part of this guide: The installation process – Booting Debian and choosing a Desktop Environment.