windows 10 major update wiped GRUB, how do I recover partitions properly? [duplicate]

Windows 10 + Ubuntu 16.04 LTS dual boot on a Lenovo Laptop.. after getting nagged about an update... I have been dumped into the grub rescue screen

grub rescue>

and a lot of the help for dual boot linux users seemed to rely on ls showing you a valid partition.. none of the partitions I am seeing are returning as valid file systems

grub rescue> ls
(hd0) (hd0,msdos5) (hd0,msdos3) (hd0,msdos2) (hd0,msdos1) 

grub rescue> ls (hd0,msdos5)/
error: unknown filesystem.

I am told I should grab a USB live stick.. boot in .. but a little bit uneasy since most of these walkthroughs are from 2015 & seem to get people stuck..

Windows 10 upgrade led to grub rescue

can someone nail down exactly what is the proper procedure ..

UPDATE 1

I tried to utilize the boot-repair utility, used the default repair.. shutdown and restarted.. didn't work, still seeing grub rescue and the same partitions as before

UPDATE 2 Now going through testdisk, here's the latest output

http://paste.ubuntu.com/25572230/

UPDATE 3 Performed the quick scan, my files are seemingly there.. but when I do the deep scan I get this warning

Leaving everything marked for deletion.. in my experience I need to select the partition with the boot file in the root dir to be bootable, and unmark for deletion all the rest...

Windows 10 Anniversary Update, and the more recent Windows 10 Creators Update, have a really bad habit of wiping out Linux partitions on MBR disks. Sounds like you're a victim.

Recovery is possible, but it can be tricky.

Boot to the Ubuntu Live DVD/USB.

Open Software & Updates and make sure that all of your software repositories are enabled.

In terminal...

sudo apt-get update # update the software database
sudo apt-get install testdisk # install testdisk
man testdisk # read the manual
sudo testdisk # start testdisk

You can also get specific instructions here: http://www.cgsecurity.org/wiki/TestDisk_Step_By_Step