My Cloud Home is found as drive Z:

The My Cloud Home is attached directly to the internet router. However, I have a secondary router that controls all wireless access. WD Discovery cannot locate the My Cloud Home. I cannot create an automatic backup. I use Windows 10 on a Surface. Is there a solution???

Yes, operate your secondary router in bridge mode instead of routing.

Also if you are using Windows File History it will not be able to backup to the MCH mounted drive. You will need to use the default public share to use windows file history. see the article below

https://support.wdc.com/knowledgebase/answer.aspx?ID=20103

My Cloud Home also shows up as a Z-drive. When I try to do a backup on it (per the instructions below), My Cloud home does not show up as an option. What setting do I need to change?

I have My Cloud Home plugged directly into a Asus Dark Knight N900 router. All of my computers are wireless connected to this router.

image