Multi boot freezing at startup

[randalf]

When I installed OSX El Capitan (all working fine), Clover was of course automatically installed.

Next, I installed Windows 10 and this created a number of Windows boot options that won't work.

Then, I eventually installed Unbuntu 15 and this created a link to yet another bootloader Grub

As a result, the machine started to intermittently freeze at statup and once Grub was installed it would always freeze once Clover gets loaded.

When it freezes, this exclusively happens at boot time and even in the BIOS as I just have about enough time to get into the BIOS.

Clearly, this is not an issue related to parts or something faulty but the multiple boot options are the root cause.
A number of other users reported other freezing issues but those posts appear to be hardware related and happen intermittently while using their machines and this did not match the symptoms I am reporting in this post, hence this new post.

The workaround is to plug the USB Unbuntu 15 installer and the machine stops freezing and I am able to use Clover again or else exit Clover that takes me to the other boot loader where I can either boot Unbuntu 15 or Windows 10.

As I strongly suspect that other people in this community experienced the same issue, I was wondering if someone could get me in the right direction.

Most likely, this will consist in editing Bootloader configurations.

Thanks
R

 

[Going Bald]

At the Clover selection screen you must select the correct icon to boot Windows - the one that is labeled Boot Microsoft EFI boot menu from EFI is the correct one. There is no need to exit Clover to boot Windows. You can use Clover Configurator to create custom entries to hide the unusable Windows icons. For the Linux install, did you install it UEFI?

 

[randalf]

Thanks for your quick feed back, literally within minutes after I posted.

I understand, so this is possible to edit Clover and amend incorrect boot options.
I will certainly look into this. Actually, I think that there are no correct Windows booting options, none of them work.

To answer your question, yes I believe that I used an UEFI Unbuntu installer
Here are the exact steps I followed to create the USB Unbuntu installer

http://www.pendrivelinux.com/universal-usb-installer-easy-as-1-2-3/

 

[Going Bald]

Thanks for your quick feed back, literally within minutes after I posted.

I understand, so this is possible to edit Clover and amend incorrect boot options.
I will certainly look into this. Actually, I think that there are no correct Windows booting options, none of them work.

To answer your question, yes I believe that I used an UEFI Unbuntu installer
Here are the exact steps I followed to create the USB Unbuntu installer

http://www.pendrivelinux.com/universal-usb-installer-easy-as-1-2-3/

If your pendrive installer is forcing MBR instead of GPT and FAT formatting then I doubt it is installing EFI.
I usually use a DVD, but I realize some do not have a drive and must use USB.
Is there any means of forcing EFI install if you do a manual install setup instead of alowing the installer to erase/format/install on its own?