Just unpacked my TS-453A after 7 years in a box...

I used it for a semester in the 2016/17 school year to help manage pictures in my yearbook class, then packed it up and put it on a shelf. I want to check it out now - either sell it or start using it again. When I last used it, one of my students was an expert at using it, so I did not have to learn much about it at all. My questions:

  1. It takes 5 minutes to boot up. Is that normal? It is not hooked up to any network now.
  2. When it finally boots up, the screen says “you must install HD Station before using HDMI output function.” Is this what I should see? How do I erase the 2x1 tb hard drives and have it blank for the new use/user (still not sure what I will do).
  3. Is the operating system on one of the 2 disks? or is it stored in a chip? Can I take the 2 hard drives out, connect them to another computer and erase them?