Hp won't turn on unless both hard drives are installed

[Cfb_rolley]

So I received an old PC from work which works fine, but I was hoping to swap out the drive that doesn't have windows installed for a different hard drive. But if either of the two drives are removed or swapped with my drive, the PC won't boot at all. Just 4 beeps/red light flashes, pause, then repeat.

Is it possible the drives are in a raid setup and bios won't allow the PC to turn on unless the correct drives are installed? How can I get around this?

 

[WyomingKnott]

It's possible that it's in a RAID, but unlikely. I suggest that you boot to Windows and look in the disk manager. If you see one drive they are in a hardware RAID. If you see two, it's a different issue. Can you tell us what the disk manager show?