Okay. This will be a little bit complicated. But try it. It may just work out. I hope you have no data in the HDD there.
Enter system installing interface by using Win 10 USB hard drive boot. and then press “Shift”+”F10” to open the command prompt.
Type “Diskpart” (do not input quotation mark os any of the suggested commands), and then press “Enter” key to enter operating interface.
Then type “list disk”: to check hard disk properties. Pay more attention to capacity of hard disk to select. Usually, disk 0 is hard disk, and disk 1 is the usb drive where wins 10 is in.
Type “select disk 0”: to select disk 0 as the disk that is operating System needs to be installed in. In your case, you need to note down which is the drive you want...