WD Passport 4TB - doesn't allow the password setting

Hello,
I have bought a WD Passport 4TB, it works well, but there’s no way to set up the password for the access. I have followed the advises and the instructions on this website, but still I find no way to set up a password.
Now, again, I have re-intalled the software of WD Discovery , downloaded from the WD Support Downloads website. When I start it, a window informs me that “this App can’t run on your PC. To find a version for your PC, check with the software publisher”…
I’m using now a netbook with Windows 10. Can you please advise me what software to install, just in order to set up a password ??

thanks a lot,
Marzio