Rufus: Error message Revoked UEFI bootloader detected with Windows 10 ISO

Rufus complains when creating a freshly downloaded Windows 10 ISO file.

Today I wanted to put a Windows 10 ISO file on a USB stick, but the message came up that the ISO file has a “Revoked UEFI bootloader detected”.

Revoked UEFI bootloader detected

Rufus detected that the ISO you have selected contains a UEFI bootloader that has been revoked and that will produce a “Security Violation” screen, when Secure Boot is enabled on a fully up to date UEFI system.

– If you obtained this ISO image from a non reputable source, you should consider the possibility that it might contain UEFI malware and avoid booting from it.

– If you obtained it from a trusted source, you should try to locate a more up to date version, that will not produce this warning.

OK, maybe my ISO file was too old? So I downloaded a new one from Microsoft using the Media Creation Tool. It turns out that the ISO file was up-to-date and there is nothing newer.

The background to this is probably that Microsoft had security gaps in its stuff, and therefore the bootloaders are no longer classed as secure. According to Reddit, Microsoft has not yet fixed this, and it is also questionable whether they will do so with the upcoming end of support for Windows.

With Secure Boot activated and up-to-date, it can therefore happen that the boot no longer works or no longer works at some point. The remedy in this case is to deactivate Secure Boot.