Follow the instructions to run the "Smart Drive" test, and note if any tests fail. Since you have a new drive, I would think that HP's conclusion (if all tests pass) is probably right; that a shock or something caused the bios to display this error when there was no real error. But definitely run the tests. Report back if you would, too.
If the tests pass, it's probably safe to say you have a working spare hard drive now (your original drive).