I have a Lenovo P51 laptop here (currently running Microsoft Windows 10) on which I'm contemplating installing Linux - probably Arch Linux, or perhaps Debian Testing - or another distribution that is kept fairly up to date. Arch is of interest in that the packages are kept fairly close to upstream, which could be useful for some of my purposes (e.g., reporting bugs on accessibility-related tools such as braille display software and screen readers, and compiling development versions thereof). I need to keep Microsoft Windows around for work purposes, due to compatibility issues. I'm contemplating a dual-boot configuration. I would rather not turn off Microsoft's virtualization-based security, which requires Secure Boot to be enabled; unfortunately, there are too many vulnerabilities and plenty of Windows malware is circulating. On the Windows side, I have enabled Device Guard and Credential Guard in local group policy, set to require "secure boot with UEFI lock". I don't know whether this will complicate Linux installation, or whether it will need to be disabled, even temporarily. At this point, neither an Arch ISO image (written to a USB drive with dd) nor a GRML64 image will boot. I suspect Secure Boot is responsible, unless of course this system cannot boot from these prepared ISO images. I've read documentation on the Arch wiki and elsewhere about UEFI and Secure Boot, most of which is not very clear or somewhat incomplete. There are several boot loaders from which to choose, for example, as well as complications with Secure Boot. I've installed Arch before (and Debian more than once), but only on BIOS-based systems and never with another operating system also present. Further, there are various reports of mixed success with Linux on this particular laptop model. It isn't clear what information is up to date. Also, I want to avoid corrupting the UEFI firmware or data in ways that would necessitate board replacement; I've had to deal with unrelated hardware issues recently and definitely don't want to have to go through the pain of that experience again, if I can avoid it. So, what would be my best source of advice at this point on how to proceed? Suggestions and links would be welcome. I'm also willing to discuss it with someone who knows UEFI well, if necessary.