Moreover, I've already tried using Photorec to recover my files but no luck there either. Please have a look at them and suggest next course of action. I have uploaded a few images and the log files from both versions. I don't know how to back up the data as there is no partition.

Would you advise using the 'Write testdisk MBR code to first sector'? I also selected the No partition option and tried to create an image of the disk, but the image it created was 0 bytes. It is a regular USB drive, I did not make any partition on my own. There are no options available in the Advanced menu as no partition has been found. Quick search and Deeper Search does not find any partition as well (both versions). I have used testdisk 7.0 and 7.1 and no partition has been found. Running chkdsk shows that it is a RAW drive now. When I tried to use the drive again the computer wanted to format the drive. I unplugged the USB drive and shut down my computer.

I was transferring a few files to the USB drive when my computer froze.

But I haven't had any success recovering my files. I wanted to thank you for making this software available.

Sades 7.1 cannot find any device