XPS 8900 - Inaccessible Boot Device

I had a problem where my XPS 8900 would not power on. I sent it back to Dell for repair. To protect my private data, I removed the hard drive before sending it back. Dell replaced the processor and shipped it back to me. I put the hard drive back and powered the PC on. Now I get the Inaccessible_Boot_Device error.

I tried the following:

1. Swapped in a different SATA cable.

2. Plugged the SATA cable into a different port in the motherboard.

3. Checked the drive for errors and didn't find any.

4. Restored a system image to the drive.

I have another hard drive sitting around and my next step is to install Windows 10 on it to see if it will boot.

Is it possible that the Dell tech changed some BIOS boot settings and I just need to set them back? What settings should I check?