How to set up MyPassport

Bought MyPassport 4TB - opened sealed box found no paper instructions on how to set up. Only files on drive were Discover for PC & Discover for Mac. I run Win7 and clicked on Install PC Discover but got (multiple times) Error popup. Online Chat with WD Support said Discover is not supported on MyPassport, that I should download Backup from web. I did that & seems to be working (still multiple hours under initial backup - no “progress” indications on PC monitor, but LED on drive seems to be blinking, so hope it is working – I’m entering this note on a different computer). Question - if Discover is not supported for MyPassport on Win, why is it the only program on the disk and why was there absolutely no QuickStart or UserManual?