I have been searching the extensive forum on this topic and found many threads on the subject. However, since I am relatively new to these things I want to make sure an answer is tailored for my needs as I don't want to do anything hasty from another thread that maybe isn't exactly as my situation. I hope you don't dislike me for being kind of selfish in this way!
My situation is that I have an old 1TB HDD with Windows 7 OS installed that I would like to use as a secondary hard drive (for games, movies etc.) in my new computer. In this I have an 240 GB SSD with Windows 8.1 OS installed.
So my question is: what do I need to do with my old HDD in order to use it safely as a secondary HDD?