Giving us specific info about the computer and its configuration would really help it wouldn't be a Dell by any chance, would it?), but here are a couple of general thoughts:
1. "Cover previously removed" is just a warning message that some computer's will give you to indicate that the case has been opened before. The "warning" is harmless, and you should find a place In your BIOS to turn that notification off.
2. If the computer only has one drive installed, it will be "Drive 0". Again- look in the BIOS for anything related to detection of a second (possibly SATA) hard drive. If you find such an option enabled but have no second drive installed, disable that option.
3. It is perfectly normal for the BIOs to identify installed hard drives as "Auto" or "Auto detected".