Linux – Windows 8.1 fails to boot after Linux Mint 17.1 install

installationlinuxpartitioningwindows 8

My brother wants to move to Linux, so he installed it on his second HDD. The second HDD was the boot sector drive, but Windows and all the data was on the first HDD. After installing, Linux would boot, but not Windows 8.1 .

So, I booted from the Windows Install disc, and ran startup Repair, which told me it failed, with no other explanation. I then tried other advanced options from a command prompt window, using diskpart as per How can I repair the Windows 8 EFI Bootloader? .

bootrec /scanos found the Windows install on C:
bootrec /fix executed OK, but
bootrec /rebuildbcd told me it failed.

And, now, Linux will not boot, either, but I can easily re-install Linux

How may I recover the Windows Boot instructions?

I do not know if this is relevant, but here's the partitioning:

sel vol 1

should show me the four partitions on sdb but instead I get the same as

sel vol 0

i.e., sda1 through sda11

sda1 Extended
sda5 – ntfs D:
sda6 – ntfs E:
sda7 – ntfs F:
sda8 – ntfs G:
sda9 – ntfs H:
sda10 – ntfs I:
sda11 – ntfs J:
sda2 Primary, ntfs, C:

sdb1 – fat32 Boot
sdb2 – ext4 /
sdb3 – ext4 /home
sdb4 – swap

Best Answer

Hmm, this is a typical case if you don't know how these installers work. But don't feel bad. I have seen that many times because the causes are not obvious.

Let me first explain what has happened and then we'll see how to fix it.

When you installed Windows, the disk on which you installed was not on the Sata port0. The disk on which you installed Linux was on that port. But the Windows installer has this habit to install the bootmgr (the 350MB EFI system partition) on the first disk (the one with the lowest port number) it finds. The remedy is to either switch the Sata cables on the mobo or to disconnect the disks on the lower ports during the installation.

Then you installed Linux on the port0 disk. The Linux bootmgr is the Grub which did overwrite your Windows bootmgr. If you are a Grub expert, you can fix that, but we will try to do that in another way.

Download the bootable CD iso of Partition Wizrd and burn that to CD. Boot your PC with that CD and mark the C partition of Windows active. See the steps in the picture below.

Now run a startup/repair 3 times. Then try to boot Windows.

Next time you install Linux on the port0 disk, unplug the disk where Windows is. Or even better and a lot more flexible - install Linux in a virtual partition. That is completely trouble free and will not present any such problems as you have seen. Here is how. In this tutorial I also use Mint.

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