Hard drive fully wiped clean after transfering into another PC

My hard drive was fully wiped clean after moving it to my another PC.

Before, I've had this secondary HDD as my games directory on my old PC. I wanted to copy those games into my new PC so I tried to remove it from the old into the new one, thinking I wouldn't run any problems in Windows as it doesn't have a Windows OS in it.

After I migrated the drive, making sure all ports are plugged in, I tried to boot up my PC. It detects the hard drive, it even has the name I assigned into it, same goes for the drive letter. The storage allocation is the same as before, but opening it shows it is completely wiped, no hidden files as I checked it (besides the two hidden folders recycle bin and system volume information). Restarting doesn't help at all.

Any thoughts on what might have caused this?