grub fails to boot after Windows upgrade

Solution 1:

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

Update:

Your missing Ubuntu partitions were between partitions 4 and 5, and went from 1015GB to 1983GB-1.