im not a tech expert so i need help. my custom built pc (windows 10 it has nvidia 16gb ram "1tb space") i looked inside it because i got a spare hard drive from a friend to install it but there was allready another 500gb hard drive there but my computer only showed up as having 500gb (there was 2 500gb hard drives in the slots, plugged into the motherboard so it shouldve been 1 tb) ive looked in disk management on my pc and computer management and it wont show up and whenever i scan i can only hear 1 thing spinning (either motherboard or drives idk) please help. i have no idea why it wont pick up the 2nd hard drive. i wanna see if i can get some help online before reinstalling the drive manually and seeing if it picks it up. (also i have NO replacement wires to connect hard drives to my motherboard because my friend didnt have any spare) please help