I transferred approximately 3 TB from my 4 TB to my 8 TB drive over 16 hours. I then began to transfer my approximately 4 TB from another drive to my 8 TB drive I left to wait as my computer gave me an estimated time of 48 hrs I came back to check on it a couple hours later and my screen was black but the PC was still on with moderate to heavy fan use. I need to know what to do. I need the data from those drives and I am not sure if turning my computer off would corrupt them I need to know what to do and what I should expect to happen. My PC is pretty old probably from the late 2000s. I don't know much about he hardware of the computer itself.