I found some old answers, but I think it is justified to ask this for 18.04. I had Windows 10 + 18.04 as dual boot. I tried to change an empty NTFS drive to ext4 and everything collapsed. I don't know whether it was me or gparted a bit too difficult to use. Everything died and the laptop was useless.
I installed Windows 10 in an empty partition and somehow the process brought back most of the drives. I still have an NTFS and ext4 drive to recover. I tried partition recovery wizards on Windows 10. Most of them are pricey.
Is there any tool we can use from an Ubuntu live USB which bring back these 2 or at least the NTFS partition back ? Thanks.
PS : The lost partitions remain untouched under a 176 GB unallocated space.
Update 1 :
This is where I am now, how to proceed ?
