Latitude E6510, 2nd HDD to corporate-proof my laptop?

Can't you press f12 at startup and pick the 2nd hard drive and boot from it? I've done that before. As long as it's in the media bay. I made a bootable cloned HDD in the Media Bay from installed HDD then on start up choose boot option for media bay.
Or like he said swap out the HDD's. On my C640 I hard two HDD bezels so all I had to do was slide then out and in. I didn't have them screwed in. They seem to stay but you can throw in one screw and it will stay.

 

Yes u can (and it should be the case for normal operation/use) , but the issue here is during the OS install. A careless person has a chance of "formatting" or "installing" on the wrong drive .