PDA

View Full Version : Boot problems after Windows 10 latest upgrade



magdaleen-ballot
January 20th, 2018, 12:53 PM
Good morning,

I have a dual boot: Windows 10 / Ubuntu 16.04.
After the latest upgrade of Windows 10 I got into grub rescue mode, not being able to run either Windows or Ubuntu.
I opted to try and restore grub using the Boot-repair disk, opting the 'Recommended Repair'.
The url on the info at that stage is:
http://paste.ubuntu.com/26416416.

After this I got Windows to run immediately but no grub menu (and hence no option to start Ubuntu)
The 'BootInfo' summary I did after this can be found at:
http://paste.ubuntu.com/26421385

I would rather not re-install ubuntu, so I would be greatful if somebody can help me out here.

Kind Regards
Magdaleen Ballot

oldfred
January 20th, 2018, 04:34 PM
Windows had a bug going back years for BIOS/MBR installs.
It "forgets" to write Linux logical partitions back into partition table.

/dev/sda4 583,417,854 1,250,263,039 666,845,186 5 Extended
/dev/sda5 1,224,990,720 1,250,263,039 25,272,320 82 Linux swap / Solaris



If you only had one Linux partition it starts two sectors after start of extended and ends somewhere before start of swap.

backup partition table before any changes, so you can get back to current if changes not correct
sudo sfdisk -d /dev/sda > PT_sda.txt
So you know sectors:
sudo parted /dev/sda unit s print


You can use testdisk or parted rescue to restore.

Another user just posted with same issue.
https://ubuntuforums.org/showthread.php?t=2382978&p=13732318#post13732318

Used parted rescue
https://ubuntuforums.org/showthread.php?t=2362656
http://ubuntuforums.org/showthread.php?t=2315405