I have a crucial 256 GB SSD and a WD Green 500GB HDD from about 2012. It does not matter which drive has the OS installed (Windows 10) storemi will always fail to create the tierdrive. I cannot get passed this step in the process, although both drives will appear afterwards as "captured". The SSD will be visible as a UEFI mode bootable device in the bios but the HDD will not. I cannot extend either drive afterwards.
I think maybe this old HDD does not work with storemi? Would that be correct?