Can't access files on WD My Passport

When I plug in My Passport the computer recognizes it and it shows up in my devices, but when I go to look at the files it doesn’t show up as a drive.  

You can try running a DLG test to verify if the Passport has any hardware problems, if the test completes successfully the problem could be caused by corrupted files. If you need to recover your files, you can try using a data recovery program, using Google you can find several options, if not, you should be able to format the Passport from the Disk Management window. Check the link below for the steps. 

How to test a drive for problems using Data Lifeguard Diagnostics for Windows

How to partition and format a WD drive on Windows (8, 7, Vista, XP) and Mac OSX