Plug in -- can't play?

I plug in My Passport WD but the interface to the software doesn’t appear. This drive is 3 years old and I have used it to backup my files several times - the last being 3/11/2016. I can see the device in Devices and Printers and can open it.
I want to run another backup but can’t without the interface. Any help would be much appreciated.

There have been changes to WD Snartware, if that is what you used. Check downloads for latest version, but be careful, because some features were removed.