I added two new Seagate Desktop 3.5 inch 2TB 7200 RPM 64MB 6GB/S Internal SATA Drives to my Dell XPS 8700 desktop.
The BIOS seems to recognise the original 2TB drive as well as the two new ones.
In Windows(10), only one of the new hard drives shows up, and the really puzzling thing is that from time to time it switches from one new HD to the other, but only ever showing one.
I've checked "Disk Management" and Device Manager to see whether the other drive is listed in any way and it's not. The only thought I have is that both new drives have the same "Device ID" shown in the BIOS, although attached to different SATA ports.
Tried running Memory Diagnostic, didn't help. All cabling seems is correct as each of the new drives shows up at different time.
Dr. Google hasn't helped. Puzzled to say the least.