Appears to have lost all data, not sure if Passport Essential is working

I turned on my iMAC and got a blank white screen, I assumed I lost all data. I realized I didn’t know how to access the WD SmartWare. I followed Apple’s directions to restore data from an external drive used with Time Machine. An icon of a USB appeared, when I clicked it; several minutes went by and icons of a folder with a question mark on it started to appear every every 40 seconds or so. Is this an indication that the Passport is restoring, (very slowly) all files? If so will it restore the OS as well? I think I set it up for a complete restoration. I would greatly appreciate any help the Community provides. I thank you all in advance.

The Time Machine software will restore the entire computer if a backup was done using the same application.

Otherwise you will have to manually restore the files from the drive once the OS has been installed.

For information on how to restore a backup with Time Machine: