On Windows systems with BitLocker, booting off an external drive (or shoot, even opening the bios to look and see how much RAM was installed, as happened to me

On Windows systems with BitLocker, booting off an external drive (or shoot, even opening the bios to look and see how much RAM was installed, as happened to me once) will often trip the BitLocker recovery prompt which means you have to call IT and ask for the magic 48 character password to get back into your laptop, to which they inevitably ask "why did that come up".