# Install and Boot Windows 10 with UEFI and FreeBSD with Legacy



## ldgc (Jan 17, 2018)

Hi 
For using Windows 10 at work and FreeBSD at home with my laptop on real hardware, I intend to create two primary partitions on HDD: one for Windows 10 and the other for FreeBSD.

Observations:


My laptop has secure boot enabled and it is not possible to disable it on Acer’s bios setup “InsydeH20”, so the mini-memstick.img only boots with Legacy.
The product key is stored in BIOS and will be used automatically by Windows 10 when connected to the Internet, so activation isn’t a problem.
HDD’s size is 932G.

Questions:


Is it possible to install and boot Windows 10 with UEFI on one partition and FreeBSD with Legacy on the other partition?


If the answer for 1. is yes, then for using a web browser, a torrent client, video and music players, games that are not resource hungry, software of work and a VM on Windows 10 and for using FreeBSD's base system, what is the recommended size for each partition?
Thanks in advance!


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## Sensucht94 (Jan 17, 2018)

pensador_13 said:


> Is it possible to install and boot Windows 10 with UEFI on one partition and FreeBSD with Legacy on the other partition?



Despite:


booting a MBR disk with UEFI is possible, flagging the MBR sector as MBR partition type for the "EFI system partition" (0xEF) 

booting a GPT disk in BIOS is possible too, thanks to the protective MBR s located at lba0
That is to be discouraged because:

chances are high you'll run into major issues, especially in the second case, with a GPT disk on BIOS or CSM/Legacy_BIOS mode
One one hand Microsoft does not allow booting Windows from a GPT partition table in BIOS,or with BIOS mode enabled. On the other hand, if booting Windows on a MBR disk, the install wizard will automatically and forcibly try to make a EFI partition and install the Windows boot manager on the latter, instead of appending the partition scheme to the MBR and install the Windows boot Manager to your C:\ partition
Hence, albeit being feasible (and risky) with other OSs, it's not possible with Windows unfortunately

*Possible solution*: if you are so lucky your motherboard supports *CoreBoot * (rare occurence), replace your UEFI with Coreboot + *TianoCore* as *payload*, and dual-boot  Windows+FreeBSD in UEFI mode (Tianocore emulates UEFI) on a GPT PT using Grub2 as bootloader from FreeBSD.

Alternatively use *SeaBIOS* as payload for Coreboot, in order to dual boot FreeBSD+Windows in Legacy_BIOS mode, then use *EasyBCD* as bootloader  from Windows system partition (EasyBCD does not work on UEFI,so can't be used with Tianocore)


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