Error message when I try to eject

I have a Passport which I´ve had for 3 years with no problems.   Now I can´t eject unless I turn off the computer.   I use the passport to save all my files as I work in a number of different places on different computers and to turn the computer off is a great inconvenience.   The error message says that it is in use - but it isn´t.  I need step by step instructions as I´m a bit green when it comes to the techn ical language!!

Thank you

You can try the suggestions provided on the link bellow in the WD Support Website:

Are you using any type of automatic backup or sync software that may be running in the background? Go into the Device Mianager find the drive and right click for properties then check the Policies tab and make sure Write Caching is enabled.