I run Win 7 Pro 64X on a Dell Studio XPS 9100. I use a Samsung 840 Pro boot drive and all data is on separate drives. I bought a new WD Black 4 TB to use as a new data drive. When that drive is installed internally the system will not boot. When I remove it, the system then boots fine. I installed the drive in a USB external case and it work fine.
I’d really like to figure out what’s preventing the system from booting. I believe I have all of the necessary SATA drivers and my BIOS is up to date.
I have the same situation with an HGST 4 TB drive
Both drives are GPT.
This problem all started when I did a clean install of Win 7 Pro on the SSD. Before that, a 4 TB drive (the HGST) worked fine internally.