Data difference between my computer and My Passport

My computer has two drives, the C: drive (222 Gb), and another partitioned 1Tb drive called New Volume E: The total amount of data on both is 225 Gb. But My Passport has 679 Gb, or about three times as much, and seems to increase regularly.
Why the big difference, and should My Passport be cleaned up somehow? You’ve probably guessed by now I’m not too good at this. If, for some reason, I lost all my computer’s data, I wouldn’t have any idea how to access, or transfer the lost data from My Passport onto a new computer. I bought, and installed My Passport years ago, and it’s just sat there ever since increasing in data content. If anyone can explain what’s happening, and what to do if I ever need whatever backup is stored, it would be appreciated. Please, keep it simple.

Thank you…Dave

Hi @David_McCauley,

Have you opened a Support Case? If not opened, for more information, please contact the WD Technical Support team for the best assistance and troubleshooting: