The HDD is labeled as B: and it only has 579MB which is very weird considering it has 1 tb, but it also says 930 GB not allocated. What does that mean? And when creating a new SteamLibrary in steam it says i only have 542MB. I would really like to use all storage.Your OS is on the SSD?
What are you looking at to store on the HDD?
Generally, it is pretty easy. Windows and applications have gotten really good at using more than one drive.