I am using a dual boot laptop with 14.10 and Windows 10. After Windows update, first reboot got me to grub rescue> prompt. I have checked previous posts how to force boot into Linux. In all those cases by progressively searching through partitions people found their Linux partitions. My problem is I can't seem to find it.
This is what I get after set and ls commands.
It seems before the update boot partition was msdos6. Now I check every partition (msdos1, msdos2 and msdos5) with ls command to find the partition with grub but get error: unknown filesystem. for all of them.
ls (hd0,msdosX)/boot/grub
I will use a live CD to recover as last option.
https://sourceforge.net/projects/boot-repair-cd/
I'm afraid I have to recommend the last option. Boot-repair is very easy to use, the automatic option is usually enough
Another way is to start Ubuntu with Supergrubdisk http://www.supergrubdisk.org/super-grub2-disk/ And repair grub from the terminal
You've probably been hit with the notorious Windows 10 Anniversary Update. This update is known to sometimes wipe out Linux/Ubuntu partitions (why? only Microsoft knows). If you can post a current-window-only screenshot of gparted, I can confirm this case.
Recovery, short of reinstalling Ubuntu, can be difficult, but it may be possible through the use of the testdisk application. Search AskUbuntu for "testdisk" to read what others experience is.
To run testdisk, you need to boot to a Ubuntu Live DVD and install testdisk. Once booted, you open a terminal window and type the following three commands, one at a time. Suggest copy and paste.
sudo apt-get updatesudo apt-get install testdisksudo testdiskFor a step-by-step intro to recovery using testdisk, visit http://www.cgsecurity.org/wiki/TestDisk_Step_By_Step.