Since I went from Linux Mint to Windows 7, my HDD for storage no longer works. It took ages to boot Win7 with it connected, or sometimes not at all. With the HDD disconnected and only the SSD boot drive, it takes seconds. It will not show up in the BIOS. The HDD is NTFS, as I had Windows 10 prior to Mint, and never formatted it. The HDD works in my Dell OptiPlex running CentOS. I ran SeaTools and the long test revealed bad sectors. It was unable to repair it, so I tried wiping it, (backed up important files first) but the desktop still won't boot when it is connected.
The drive is a Seagate Momentus 2.5" 7200rpm 750GB from a 2010 Dell XPS laptop.
MSI 970 Gaming Motherboard
2x4 GB RAM
Corsair Force LX 128 GB SSD
EVGA SuperNOVA 750W PSU
Windows 7 Professional SP1 64-bit
Dell OptiPlex 780
Intel Core 2 Duo
2x2 GB RAM
Currently running SeaTools long test on the blank HDD. (It's been going a while, last time it failed immediately, so it looks as it may pass)