Cannot defrag WHOLE drive

[MCK]

I can defragment only the Admin files.  Other user files don't appear in the Degraggler File list.

I logged in as another user, and Defraggler insists that I can use it only as Admin.  I tried "Run as Admin."  That ran, but showed the same file list as when I was logged in as Admin -- namely, it did not show the files for the non-Admin user.

While logged in as Admin, I enabled access to the files of the other user.  I am able to open files of the other user (in Windows Explorer), but Defraggler doesn't list them.  (Except, it does list AppData files for the other user.)

Rebooting didn't help.

How do I defrag files for user accounts other than Admin?