Thank you Fiona, chkdsk was able to recover the entire partition!
This is is the second time this happens, the first time occured after migrating a Windows partition into another drive, Windows decided that this "storage" drive was the boot drive and tried to repair it during boot. TestDisk was ...
Your animated gif is too fast to watch. That's why I have no idea which partition do you want to recover? Do you have a partition in your partition table (even GUID partition table)? Does your current partition differs to that partition testdisk finds (during Quick Search). For exfat there is ...
Christophe the partition is back, however Windows mistakenly tried to "repair" the hard drive during boot, and now it shows up as a Windows primary partition even though it does not have an OS.
Is there a way to get rid of this leftover MBR data and remove the drive from the boot list?