Not sure if the “cover” of your hard drive has been opened?

Left side = hard drive cover is on/unopened. Right side = hard drive cover is off/opened.

NOTE: the “cover” is different from the “enclosure” (the latter is only present on “external” drives).

The “cover” is the metal part of the hard drive that conceals the platters/heads (photo above).

The plastic or metal “enclosure” is only a “shell” that conceals the hard drive, and this is okay to remove (photos below).