My laptop is configured so the C (main) drive is encrypted. I carry it a lot around in public a lot more now, so I was just wondering (although it may be obvious) if using pre-boot authentication (like a PIN) would be a good idea. Despite encryption, I'm not asked for passphrases or PINs, rather I use just a local Windows login password. I think it is just done in the background as BitLocker says it's on. However I don't think a generic, local Windows password would protect against a physical attack if somebody stole it.