Hello I am relatively new to Apple having used Windows for decades. As photos have become my focus now I went for the Mac updated to 10.10.5. I also purchased a My Passport 1 TB backup storage and a Seagate Backup Plus slim 1 TB. Ive been able to install and set up Time Machine which accepts using both for preforming the backups. Ive checked that they are indeed backing up and run disk utility checks etc. My issue is that when I go to access the files on these drives the only one I can view is the initial complete computer backup. Although current backup dates are listed by each device no alterations to the files has been recorded. Each backup lists no size of the data in the file. Nor does the total data space change on the drives. Ive tried absolutely everything I can read in books, online and thru YouTube to attempt to understand and fix this myself. but no one addresses my problem or when they do, i follow the steps and certain performances to click on either are greyed out so unavailable or they don't appear at all. Please tell me what I don't know or am doing wrong, & when you do dummy it down if you can! Thank you so much in anticipation of some kind & knowledgable person's efforts.