Window 8 in efi mode and Ubuntu in legacy bios mode

Doug dmcgarrett at
Tue Oct 22 15:07:51 UTC 2013

On 10/22/2013 10:15 AM, Jim Byrnes wrote:
> On 10/21/2013 08:53 PM, Doug wrote:
>> On 10/21/2013 09:16 PM, Jim Byrnes wrote:
>>> I am again trying to dual boot Win 8 and Ubuntu 13.10 on a Toshiba
>>> laptop, though a different one this time.
>>> The only way I can get the live DVD to boot to a usable desktop is to
>>> turn off the efi boot and put nomodeset in grub.
>>> I've done a lot of googling on dual booting and find many references
>>> that basically say that both OS's must use the same scheme, ie both efi
>>> or both bios.  What I can't find is the consequences of not doing that.
>>> If it means to boot Win 8 I must enable efi and to boot to Ubuntu I must
>>> disable it, that would be ok, but I doubt it is that simple.
>>> I have found some schemes to install Ubuntu in legacy mode and then
>>> switch to efi but they are so complicated I doubt I could follow them.
>>> Does anyone have any experience with trying to install with them
>>> mis-matched?
>>> Thanks,  Jim
>> Not a real answer, but partially a question: When you turn off efi (on
>> the computer, I think you mean) does the computer "look like" it has
>> a bios? If it does, then you should be able to install Windows 8 to
>> it in that mode. I have a machine with about a 3-year old mobo that has
>> only bios, and I have Win 8.0 and Linux (pclos) installed, no sweat.
>> Boots with grub to either system--actually to Win and three Linuxes--
>> pclos kde 32, pclos kde 64, and Mint kde 64. BTW: Win 8.0 with
>> Classic Shell (free) looks just like Win 7. I think you can make it
>> look like XP if you wish, but not sure. Get KDE for Windows just
>> to get the file finder--it also has Dolphin file manager, which is
>> handy.
>> --doug
> I'm not sure what you mean by "look like it has a bios". If I leave efi 
> enabled I boot to a text mode grub menu where I choose try Ubuntu. 
> Eventually the boot process stops with a black screen and nothing 
> happens after that.  I found that some people had success by adding 
> nomodeset to grub. When I tried this I got further in the boot process 
> but ultimately ended at a black screen.
> If I disable efi and add nomodeset to grub I can boot the live dvd to a 
> usable desktop, but Win 8 is already installed using efi and if that is 
> the case you aren't supposed to install Ubuntu using csm.  I am 
> wondering what the consequences of doing that are.
> I just found a possible solution at
> It is a boot manager call rEFInd, but I will need to do a lot more 
> reading about it before I try it.
> Regards,  Jim

I guess I refer to what the url calls CSM, and says it's a BIOS
compatibility mode. I also was thinking you could install Win 8--
not that you were stuck with a fait accompli. If you have a Win8
install disk, you should be able to set CSM and install Windows
without UEFI. It would think you have an old-fashioned machine without
the UEFI stuff. (You might have to format the partition first, so
no trace of the old UEFI-Windows remains.)

Blessed are the peacemakers..for they shall be shot at from both sides.

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