There are many Folder hiding solutions. Check out this blog-
https://www.guru99.com/file-folder-locker-windows.html
Ignoring a few encryptors, most of them work by hiding the folder from Windows. You just have to select a folder and it will hide it. I suspected that they are just hiding and not encrypting because they can hide GBs in a second.
And sure enough, when I booted into any other OS (Linux Mint here), I could clearly see the folder at the exact same location and I could fully access my data [which also goes on to show how insecure they are] .
The folder simply cannot be accessed using Windows, however hard you try (even in the Safe Mode). Does anyone know how they are doing that? Also can we do that using an inbuilt cmd command or a utility like Nirosoft?