Attempted Windows 10 update, now stuck in grub rescue

Im dualbooting Mint 17.2 and Windows 8.Today I decided to upgrade to Windows 10. As You might know, during the actual upgrade, the computer restarts multiple times. On about the second restart, instead of proceeding to the grub menu, an error message popped up saying no such file system, entering grub rescue. Unfortunately, i have no clue how to use grub rescue or what to do. From what ive gleaned, using ubuntu boot repair does not help. Any suggestions?

you'll need to config grub again. put in a mint boot disk and mount the / partition of mint in the live cd/usb environment, then chroot into that mount point and run the grub mkconfig command.

do an lsblk to find the / partition. so for an ext4 formatted part it would like sort of ike this:

mount -t ext4 /dev/sdxZ /mnt (where sdaxZ is the part maybe sda3 or something)
chroot /mnt /bin/bash
grub-mkconfig -o /boot/grub/grub.cfg
exit
reboot and grub should come up

this is just a reference, check mint docs to confirm.

Thanks for the reply. I fixed this by booting into into the live cd/uusb environment, and then installing ubuntu boot repair and running the recommended repair. Afterwards, I was able to get grub working and boot into Mint, but windows still didn't show up. I updated grub from the terminal after booting into mint, and now the windows launcher shows up.

Same thing happened to someone I know. In their case, the Windows installer seemed to have deleted the Linux partition so I had to fix the partition table (using testdisk) and reinstall and reconfigure grub. Unfortunately, the Windows upgrade didn't work so we had to revert back to Windows 7 and do the upgrade again (which went fine the second time).

my apologies and i should have told ya, that's because the package 'os-prober' is in your install and for some reason not in the boot repair disk or at least in the repair disk it might need to be ran separately to find those ntfs/fat parts. glad you got it all straightened out! heck yeah!

cheers!

I had the same issue but mine appeared to have erased the partitions for linux gparted saw them only as unallocated space, I had to completely reinstall mint.

same thing happend to me that happened to @cryptonaut person they know. guess i could have fixed it with his help but w/e all my files are on my NAS so it took like 30 minutes to reinstall.