Reformatting to start over

I am sort of a newboe to this back up stuff…I bought when I had to have computer worked on and didn’t want to lose info, especially pictures. I only want to back up important info…like pictures, and documents, but not games and certain programs like print envelope program…i.e. So do I reformat which wil wipe out the back up device and then just check the boxes of what I want backed up? Like I don’t want to back up all of  "Programs (x86), but my virus program and my qucken is on there…can I select only these? 

Hello and welcome to the WD community.

In order to better assist you could you specify if you are using Smartware or a different Backup software?

I am using Smartware that came with MyPassport. I just want to start all over. How do I do this?