samuel(a)sieb.net wrote on 31-OCT-2019 22:45:56.20 > On 10/31/19 3:27 AM, Jouk Jansen wrote: >> I tried to make from my Dell lattitude E5540 running windows 10 a dual boot >> with F31. Intallation of F31 runned as expected apart form one point: I made >> a custom partion layout of the free space and it compalined that my BIOS >> needed a small biosboot partition (so I also created that one). > It appears that you booted the USB drive using CSM (legacy) mode instead > of EFI. The biosboot requirement confirms that. >> However after the installation the machine was unbootable. I had to chande >> the boot mode in the bios form UEFI to legacy to get F31 booted. Windows 10 >> appeared not bootable anymore. >> >> What did I miss? How should I proceed to get a dual boot machine? > You will need to reinstall again, but make sure you boot in EFI mode. > You should be able to set your BIOS to only boot in EFI with no CSM > available if necessary. You can remove that biosboot partition during > the install as well. Thanks that helped. CSM was called a little different in the BIOS but switching off all "legacy" capabilities did the trick. Still wondereing why Fedora installs in legacy mode while the DVD is booted in EFI mode and a windown EFI boot manager is present, resulting in wiping out the windows bootmanager.