Asus ZenBoot UEFI windows bootloader broken after Ubuntu install

[oldfred]

Because it is gpt partitioning Windows has to be in UEFI mode.

Is not this a Windows boot file? I thought only the .grb were the backups Boot-Repair made.

/EFI/Microsoft/Boot/bootmgfw.efi

As I understand it this is really part of UEFI as both Windows & Ubuntu provide it.

/EFI/Boot/bootx64.efi

[YannBuntu]

@OldFred: please read http://ubuntuforums.org/showthread.p...1#post12379441

[d43m]

Thank you, so Ubuntu removed the windows boot files, without me to say whatsoever...

I still have my recovery and my restore partitions, containing EFI files. But when I boot directly on these partitions, I have a magnificent BSOD (or almost) saying that my windows is broken. So I guess it's no use that I copy the efi files from there to my /boot/efi partition.
It looks like I have 2 problems:

1) My original efi files don't exist anymore, so it can't boot
2) Even if I boot my recovery partition it doesn't work, I guess that's because I messed up the ssd cache partition - Intel® RST (sdb1)

In any case, I will need a windows 8 repair cd / iso. And I didn't created it before... this thing is unfindable on the internet, so I'll have to go to the store I guess.

[YannBuntu]

First try with a Windows7 64bit cd, you can download one from here: https://help.ubuntu.com/community/Re...ows_Vista_or_7

(AFAIK Win7 and Win8 use the same bootloader)

[d43m]

Oh, that's good to know.

I'll try that.

[d43m]

Status update: WIndows 7 repair disc didn't work. It said that the detected OS was not corresponding.

However. I managed to find a Windows8 install disc (USB Key). So I tried to repair it, but it doesn't work. It looks like my windows8 usb key is not in GPT format (When I plug in my sony usb key with Ubuntu on it, it says "UEFI: Sony Storage..." in the BIOS and it's not the case for the Windows usb key).

I even tried to install Windows on the sda4 partition with this USB Key, doesn't work.

I guess that's not Ubuntu-related anymore...

[YannBuntu]

I guess that's not Ubuntu-related anymore...

Yes.
If i were you, i would:
1) backup documents on external disk (or DVDs)
2) then reinstall Windows8 (this may erase Ubuntu)
3) then (if Ubuntu has not been erased) recover the GRUB menu via Boot-Repair

[oldfred]

I saw that the typical Windows repair USB is NTFS, but to repair UEFI systems it needs the FAT partition as a repair. Then you should get the option to boot in either UEFI or the old BIOS mode to install or repair.

UEFI only boots from FAT partitions. The standard is FAT32 on internal devices. Small removable devices can use FAT16.

Windows 8 UEFI repair USB must be FAT32
http://social.msdn.microsoft.com/For...-166dddf32205/

[d43m]

I'm going to reinstall Windows8 not in GPT, but on a standard oldschool filesystem. I saw some posts from Zenbook Dualboot users and this should work fine. I'm thinking about installing Windows on the 500Gb HD, and Linux on the 24 Gb issd, even though the performance is not as good as on a real SSD.

Thanks for your help anyway Fred and Yann !