Can't get Time Machine to work with Nighthawk

I too am using a Seagate hard drive.  I have tried everything I can find on the internet, including the instructions shown here.  This is very frustrating!  I can see the drives/partitions and add and delete data from them, but can't see them in Time Machine.  Even if I could sign in as a "Registered User", I'm not convinced that would solve the problem.  I don't understand why the techs at Netgear can't write clear instructions that work.  Arrrrrgh!