I just purchased a new My Passport external hardware. Although the hard drive shows in Windows Explorer, the WD Backup software does not recognize the hard drive and prompts to connect a compatible hard drive. I have updated the software and drivers and rebooted. I had the same problem with another WD disk about a year ago and was told by WD Support to use the internal Windows backup (which does not work properly). I returned that hard drive and will have to do the same with the new one if the backup software does not work with the hard drive that it is supposed to support.
Can you please help us with the model number of the drive so that we can check the compatibility of the drive with the WD Software.
The software was loaded from the disk so it should be compatible.
Please follow the instructions mentioned in the link given below and let us know if the issue still persist.