Detailed description：How to add a 2nd HD then make both drives 1 huge drive and reinstall Windows 10 on Asus Laptop with Flash Memory.
This ASUS has E402SA 32GB eMMC Flash Memory Drive
As far as I know, eMMC cannot be combined with HDD.
Sorry for any inconvenience it may be caused.
Thank you. Hopefully I can reinstall Windows 10 Home to the new 2nd 500 GB HD but nothing is working right now.