Built a PC with 2 storage drives one being the Samsung 960 EVO 250GB (C to use as a boot drive and another WD Blue 1TB hard drive (E that my uncle gave me. I want to clear the hard drive since I got permission to do so and use it as my second drive for mass storage. The hard drive shows up on Disk Manager with one primary partition and another partition labeled as "Primary Reserve". I'm afraid that if I deleted the "Primary Reserve" partition it would affect my Windows 10 OS. Also, the WD drive has Windows 7 on it since it was pulled from an old PC.