Why can't I get a FULL backup?

Yet when I take it to an electronics store, they can? This has been going on for 2 months…I have tried several times. The electronics store said my external hard drive is fine and they ere able to get a full backup…but when I get back home (30 mi away) and try to back up…it starts fine then about 1/4 of the way it FAILS? HELP…PLEASE?

Hi, which software are you using to backup? Do you have the drive connected directly to the computer or are you trying it wireless? Do you have Windows or Mac?

I have a WD My Passport Ultra (Metal Edition). I am trying to ‘backup’ plugging that device directly into my laptop. I just installed Windows 10…actually have not tried backing up since I got this Windows 10 completed. I had tried about 3 times from my Windows 7 version…to no avail…