The single bay/single drive My Cloud hard drive is formatted for Linux. One will need to use Linux (boot disc) or a Linux driver for Windows to access and read the EXT4 data partition on the hard drive. And because it’s a 3.5 inch hard drive one will need to use a powered USB to SATA adapter/docking station or a spare SATA port (with power connector) on their computer. Some additional discussion on how to access the extracted hard drive on Windows 10.
My Cloud dead, how to see content on Windows 10?
https://community.wd.com/t/my-cloud-dead-how-to-see-content-on-windows-10/175311
There are various programs for reading Linux EXT4 partition on Windows, here are a few:
Ext2Fsd: https://sourceforge.net/projects/ext2fsd/
Linux Reader: http://www.diskinternals.com/linux-reader/
Ext2explore: http://sourceforge.net/projects/ext2read/
Paragon Linux File Systems for Windows: https://www.paragon-software.com/home/linuxfs-windows/
Ubuntu is a popular Linux Distro one can use to create a Linux boot disc/flash drive to boot their computer into Linux:
