Which disks to wipe

[Supportsneedlove]

I'm going to be doing a fresh install of Windows on my PC. But it has been giving a lot of trouble with the windows reset features as it somehow doesn't have enough SSD space. I can't for the life of me figure out what is taking up all that space, so I have decided to just do a fresh install. I've got a boot media laying around anyway. 

 

I know that I wipe the drives in command prompt and then install windows on my SSD. My problem is all the details, like am I supposed to wipe both the SSD AND the HDD? How do I even do that? Which do I wipe first? 

Any tips, advice or information would be nice. 

I've already back up everything of value.

Cheers, Dan.

[xenonhelix]

You probably should just wipe the SSD during setup and then wipe your HDD after installation; that would reduce complexity and preserve any data you might want from the HDD.