On Mon 14 May 2018 at 13:28:56 (+0100), Chris Ramsden wrote: > On 2018-05-14 01:21, songbird wrote: > > Pascal Hambourg wrote: > > ... > >> I agree with the author. If you want to keep the existing EFI Windows > >> installation and have a convenient dual boot with GRUB, you'll have to > >> set up your favourite distribution to boot in EFI mode. If you want to > >> go back to legacy boot, including for Windows, you'll have to > >> repartition the disk to MSDOS format and reinstall Windows. > > all i know is that if your bios doesn't boot in > > UEFI mode and you don't know anything about what this > > means you can end up installing Debian without UEFI > > support and then it can be rather fun to get it back. > > > > i managed to have grub do an install to a stable > > partition without UEFI and i messed up the testing > > setup i had. it took me some while to figure out > > what went wrong and how to fix it. if you don't > > really understand grub rescue commands and there > > isn't a working system you can use to connect and > > find help for the commands you need to enter it's > > very frustrating. > > > > the Debian UEFI pages helped a great deal but > > there were other things i had to figure out coming in > > cold to UEFI. > > > > how to create a /boot/efi partition, what goes in > > it, mounting it, clearing and putting in new efibootmgr > > entries, etc. > > > > refind was useful and at least it does what i expect > > it to do. grub, i dislike how it assumed things i > > didn't want to do. alas, i didn't know how different > > UEFI was from bios mode. > > > > i still haven't redone my efibootmgr entries but > > refind doesn't care, i can create custom entries in > > that config file and they work that is all i really > > need at this point. > > > > > > songbird > > > Hmm, do you have any useful references? > > I got a new Dell computer, shrunk the existing partitions down and > successfully installed grub2 and got a windows10/Linux multi boot using > grub. Then later I tried to upgrade my Linux and soon found that I was > getting error messages about grub not being able to find necessary > features on the boot device. > > I tried to rebuild it with a clean install of Windows 10, reasoning that > if I could get it back to the original configuration, I could repeat the > original exercise. But alas, no, it remains stubbornly unable to install > grub2 alongside the windows bootloader. I got it to a state where I > could use the BIOS POST boot screen to choose a boot option, but this > wasn't the original successful arrangement where grub offered me the > Linux/windows loader choice.
Would I be correct in thinking that the BIOS POST boot screen is what you get when you hit F12 sufficiently quickly after switch-on? So are you choosing between UEFI and Legacy (compatibility) mode. (I would like to know how Dell handles what I've been reporting on with this Lenovo.) > I gave up, wiped windows and went through with a clean Linux install. I > don't really want windows that much, but it irks me that I haven't been > able to fathom out how to return to the original state in which it was > shipped. Your words hint at many things I became vaguely aware of but > totally failed to grasp. The other posters to this thread have at least > reassured me that it isn't easy or trivial to get right. This is the scenario I was trying to avoid. As far as windows was concerned, my mantra was Failure Is Not An Option. Cheers, David.
