Guide: MultiBooting UEFI

[Ghee_Whiz]

I built my Hackentosh following Stork’s Thunderbolt build. It had Mavericks and dual booted to Windows. The Windows 10 is on a separate drive. A week ago I updated to El Capitan with Clover and following Stork’s instructions located on the Tony Mac forum at http://www.tonymacx86.com/threads/u...k-ga-z77x-up5-th-gtx-650-ti-el-capitan.73112/


The OS X El Capitan runs great but on reconnecting the Windows drive the Windows 10 no longer boots even though I see a NTFS icon on the Clover boot screen. Clicking on the NTFS nothing happens.


I guess this problem is from my new Clover installation. I’m not sure what happens now. In the post number 3 after installing Windows Going Bald said to “Mount the EFI partition and rename the Windows boot manager file.” As a clueless newbie I don’t understand. How do I mount the EFI partition? Where do I find the Windows boot manager and what do I rename it to? Sorry if this is a stupid question.

 

[Flaxh]

Do your research on the SSD and see if you can find a comparative review OCZ vs Samsung. Yes, you can keep the Windows without need to re-install. Double check Windows installation - if it is installed Legacy Mode, install Clover Legacy Mode. If it is installed UEFI mode, install CLover UEFI mode.

The Samsung is better but I don't think it justifies the price difference. I can get 240gb for cheaper than a 120gb Samsung and I don't wanna spend a lot on this SSD because I'll buy a PCIe one with bigger capacity when the prices drop a bit further.

 

[egcatx]

I can't get passed the part where you're supposed to mount the EFI partition and edit the Windows boot manager file. When I open up the Disk Utility in the Mac OS, I don't see that partition listed. Any idea what's going on? I have Windows and the Mac OS installed on separate drives, both Samsung SSDs. I can boot to either using the Mac OS USB installer, but can't any other way. Thanks in advance for any help.

 

[Going Bald]

I can't get passed the part where you're supposed to mount the EFI partition and edit the Windows boot manager file. When I open up the Disk Utility in the Mac OS, I don't see that partition listed. Any idea what's going on? I have Windows and the Mac OS installed on separate drives, both Samsung SSDs. I can boot to either using the Mac OS USB installer, but can't any other way. Thanks in advance for any help.

Download EFI Mounter V3 from http://www.tonymacx86.com/resources/categories/community-software.10/

run diskutil list in terminal - determine your drive ID
run EFI mounter, <enter password> , select mount, select the drive ID for your OS X drive, click mount.

 

[Flaxh]

Just got my SSD. Looking forward to the setup now. Any final tips?

 

[Ghee_Whiz]

I have my El Capitan 10.11.5 working with Clover and when I turn on my computer it boots into OS X. If I disconnect my OS X drive and connect the Windows 10 drive, then Windows will boot. If I connect both OS X and Windows 10 drive the Windows will not boot from clover. If I try to select the Windows drive Clover says its in Legacy mode which is what I think is the problem.

Now following Going Bald's reply to egcatx I have downloaded EFI Mounter V3. And I run from Terminal diskutil list and I can determine my dive ID. Then Going Bald said, "run EFI mounter, <enter password> , select mount, select the drive ID for your OS X drive, click mount." OK I run EFI mounter selected mount for the OS X drive and clicked mount.

Please help. What do I do next? Do I run multibeast again or what? I'm new to this stuff.

Update: I just ran msinfo32.exe in Windows and see that I am in Legacy mode. I think for this to work I should be in UEFI mode. Right? If so how do I do a UEFI mode installation?

 

[Going Bald]

Update: I just ran msinfo32.exe in Windows and see that I am in Legacy mode. I think for this to work I should be in UEFI mode. Right? If so how do I do a UEFI mode installation?

Easy way:
Boot OS X with Win10 drive connected. Launch Disk Utility and format the drive as if you were going to install OS X on it.
Shut down, disconnect OS X drive.
Insert Windows 10 USB installer in USB Port.
Boot system, hit Function hot key to select a boot device
You should see 2 selections for Windows 10. Select the one beginning with UEFI.
At the install screen select Custom install, next screen select the OS X partition to be installed on, click Delete, click next. Win10 installer will take it from there.

 

[Ghee_Whiz]

Sorry but I must have misunderstood.

I booted OS X with the Win drive connected and formatted the drive. I chose GUID Partition Map and OS X Extended (Journaled)
Is that correct?

Disconnected the OS X drives and installed the Win 10 USB key. When i got to the choice of where do you want to install windows there were 3 choices:

drive 0 Partition 1: EFI 200MB type system
drive 0 Partition 2 224 GB type Primary
drive 0 unallocated space 128 MB

For the drive 0 Partition 1:EFI there was an asterisk and the message Windows cannot be installed on drive 0 partition 1 because selected disk is of the GPT partition style. I clicked delete here but could not click next because the next partition. reason was it was not formatted NTFS. Could not click format. so I clicked delete

I was only able to install on the unallocated space but then when the installation is finished it is Legacy.

what did I not understand?

 

[Going Bald]

Sorry but I must have misunderstood.

I booted OS X with the Win drive connected and formatted the drive. I chose GUID Partition Map and OS X Extended (Journaled)
Is that correct?

Disconnected the OS X drives and installed the Win 10 USB key. When i got to the choice of where do you want to install windows there were 3 choices:

drive 0 Partition 1: EFI 200MB type system
drive 0 Partition 2 224 GB type Primary
drive 0 unallocated space 128 MB

For the drive 0 Partition 1:EFI there was an asterisk and the message Windows cannot be installed on drive 0 partition 1 because selected disk is of the GPT partition style. I clicked delete here but could not click next because the next partition. reason was it was not formatted NTFS. Could not click format. so I clicked delete

I was only able to install on the unallocated space but then when the installation is finished it is Legacy.

what did I not understand?

BIOS must be set for UEFI booting. When you boot the USB, on a GA-Z77 board, hit F12 during the POST
At the select a boot device screen you should see
P0: Your drive you for Windows
USB: Windows 10 installer
UEFI USB: Windows 10 installer

Select the UEFI USB: Windows 10 installer

 

[WonkeyDonkey]

BIOS must be set for UEFI booting. When you boot the USB, on a GA-Z77 board, hit F12 during the POST
At the select a boot device screen you should see
P0: Your drive you for Windows
USB: Windows 10 installer
UEFI USB: Windows 10 installer

Select the UEFI USB: Windows 10 installer

I used this guide recently and it works 100% as described.

A couple of points of note from my own experience :

1. It works equally as well with Windows 7. I used 10.11.5, Windows 7 and Linux Mint (Ubuntu based).

2. When installing windows or Linux, its important to make sure you select the UEFI option at boot time when booting from the USB.

3. After completion, I resized the Ubuntu partition and created a further small partition which is FAT32 format and allows me to access stuff on there from any OS that is running.

This is a good guide, thanks @ Going Bald