[CLOSED] Dual boot - new Windows 10 update makes a mess

Hello all,

I have a dual boot system, ZorinOS + Windows 10 insider preview. I would like to warn/inform others with similar setups, that the latest Win10 update (build 14986, 12/7/2016) will mess up your GRUB, and you will be dropped to a grub rescue prompt after the first reboot (thank you msft).

No worries tough, boot-repair fixes everything

This is what I did:

1) boot zorin os live disk
2) install boot-repair
In terminal:

Code:

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install boot-repair


3) run boot-repair, and follow the on-screen instructions
4) If everything goes right your system is back to normal, tough in my case the Windows10 loader item was missing from my "new" grub list. This was fixed by running (in terminal)

Code:

sudo update-grub

I hope this will spare you some headaches!
Cheers!

Hi, if you had installed Zorin alongside 10 like I did a while back you would not have had that issue - I used the alternative Matthew Moore method of using NeoSmart EasyBCD Software so your windows mbr never gets messed with (nor your Zorin GRUB)

Computer hardware details (custom-built):
Processor: 2x AMD Athlon(tm) 64 X2 Dual Core Processor 4600+ : 2399.95MHz
Memory : 1942MB
Storage: sda1 - 214 GB, of which 98 GB free
sda 5 - 16 GB, of which 13 GB free - (ext4 partition)
OpenGL Renderer : Gallium 0.4 on NV67
X11 Vendor : The X.Org Foundation
BIOS: Date : 01/10/2008 Vendor : Phoenix Technologies, LTD (www.phoenix.com) Version : 6.00 PG

The problem described here looks similar to my situation. But I am wondering how to proceed in my particular case. I have located the command prompt in Zorin as described here, (though I have scarcely used a command window before), but what about going directly from the start-up screen after it says 'grub rescue>' before Zorin boots up from the USB device? Does it make a difference?

What has happened with my computer is that I have just upgraded Zorin OS9 core to Zorin OS12 core, but when I switched the computer back on I got the message:
Boot from CD:
error: file '/boot/grub/i386-pc/normal.mod' not found.
Entering rescue mode...
grub rescue>

My computer ran as dual boot Windows XP (SP3, 32-bit) and Zorin OS9, which I installed according to instructions in 2015. This was my first acquaintance with Linux. However, my main operating system in actual fact has been Puppy Linux 5.7.1, booted from a CD. It works very well, and I use it on an older laptop too. This has been largely because Zorin has always been in 'test' mode with me, as it runs a bit slow unfortunately. It often locks up after 20 minutes or so, or certainly if any demand is put on memory by running more than one activity at once, for example. I have not followed this up though as, up until now, but I would like to get further with Zorin and use the features it offers.

Dual boot was working fine, I could use Windows programs on occasion if I wanted to.

With the upgrade, I tried out and installed Zorin OS 12, following all instructions for making the bootable USB device. Checksum was correct. Bootable USB worked, and still works, fine.

Install proceeded, but at the end the screen went to text mode with approximately this message:
sdb - Cannot find something (not sure what).
sdb - Therefore 'write through'.
sda - Performing a Ubuntu installation - or words to that effect.

This message flashed slowly on the screen for half and hour or an hour or more. In the end I switched off the computer.

When I switched back on I got the message described above, that is, it took me to the 'grub rescue>' prompt.

Puppy Linux continues to work fine, booting from its CD. Zorin 12 continues to boot from the USB memory stick and seems to work fine from there.

One thing that I noticed about the installation procedure was that I wasn't asked about resizing or creating any new partitions or anything, although I had done the deletes (of linux-swap partition and so forth) as instructed. I don't know whether or not this is an important point. Perhaps the install software accepted the partition used for OS 9. All other aspects of the install worked out as described in the instructions, and everything followed as expected, until I got the message at the end. It is just possible I brushed the arrow keys or the 'delete' or 'end' key area of the keyboard just before this happened - don't know if something accidentally happened here to cause the problem, or whether that is just coincidence.

Very glad of any advice on this.

Hello vaw5,

I believe your system wasn't able to start booting from your USB, and then went on to the next boot device, your HDD probably, which as we know drops you to the grub rescue prompt.
The live boot probably failed, because you booted it with UEFI instead of old BIOS. For example, when I insert a live disk into my computer and enter the boot menu, I can see the USB drive 2 times in the list, once for UEFI, once for BIOS.

As for what happened during your upgrade, I'm afraid Google can help you better than me

I hope this helps you get going!

--

@vaw5 - please start your own thread as it would confuse visitors to see ongoing conversation when a thread has been [CLOSED] which is what I am going to do now.
@ Aiialioaiiio, If you still need help, please start a new thread. Thanks.