Siralland Posted January 2, 2016 Share Posted January 2, 2016 Hello, I have been trying to figure this out for about 3 days now. I want to dual boot El Capitan with Windows 8.1 Pro. I know that boot camp will not work with it. I have tried Legacy and UEFI booting. Problem is, Windows will only boot with Legacy but Mac will not boot in Legacy mode. I have partitioned my drive several times trying different things but I always will get an error because Windows 8.1 doesn't want to install or boot in UEFI. My boot loader will not work with Legacy though... Does anyone know how I would go about fixing this? Thanks Link to comment Share on other sites More sharing options...
fusion71au Posted January 2, 2016 Share Posted January 2, 2016 Problem is, Windows will only boot with Legacy but Mac will not boot in Legacy mode. I have partitioned my drive several times trying different things but I always will get an error because Windows 8.1 doesn't want to install or boot in UEFI. @Siralland, Most likely your disk has a hybrid MBR/GPT layout instead of a pure GPT/protective MBR ---> prevents Windows from being installed in UEFI mode. Download GDisk and follow the directions in post#359 to replace the hybrid MBR with a new protective MBR. Afterwards, install Windows in UEFI mode following the directions in this guide. Good Luck! PS Please put your hardware/software info in your signature so others can help you more easily. 1 Link to comment Share on other sites More sharing options...
Siralland Posted January 2, 2016 Author Share Posted January 2, 2016 Thank you I will try it out now How would I install that if I don't have windows installed on my computer? Link to comment Share on other sites More sharing options...
owbp Posted January 3, 2016 Share Posted January 3, 2016 How would I install that if I don't have windows installed on my computer? All the steps that fusion71au suggested are done in OS X, prior to installing Windows. 1 Link to comment Share on other sites More sharing options...
Siralland Posted January 3, 2016 Author Share Posted January 3, 2016 Ah. Well I tried something different before I tried your method but when I try and boot into Windows, it is just a black screen with a blinking underscore _ Link to comment Share on other sites More sharing options...
fusion71au Posted January 3, 2016 Share Posted January 3, 2016 If you are booting to Clover on the Windows Installer USB following my guide, you need to press the number <6> key when you see the blinking underscore. Alternatively, if you already have a working Clover on your hard drive, you can omit the steps to install Clover on the USB and boot via your hard disk's Clover to start bootmgfw.efi on the USB (“Boot Microsoft EFI boot menu from your_USB_name”). 1 Link to comment Share on other sites More sharing options...
Siralland Posted January 3, 2016 Author Share Posted January 3, 2016 I fixed the problem by using DiskPart to make a UEFI flash drive instead of Rufus. Thank you for the help though Link to comment Share on other sites More sharing options...
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