wonder if anyone can help?

hi there, i currently run a single ssd in my PC for boot and quick access storage,

i stuck in my old 1TB HDD from a while ago to give me some storage. im wondering how i can remove "system reserved" from it, i think it may have had an os install on it some years ago.

thanks in advance

Reformat it... Or if there is data, go into computer management and delete it.