I have made the HD of my old desktop PC (WinXP) to an external drive (enclosure). I have never done this before and I was prepared to face some security issues, but as the old HD got connected to my laptop it simply appeared as an external drive. I was a bit disappointed if not shocked, as it means for me, WinXP password protected login is a security gate worth nothing, as about data access. Is this different in Win7? Thanks for a short explanation.
Yes, on most operating systems (OS), not just Windows, the login password only protects the user files as long as you boot into that OS. It is trivial to remove the hard drive and connect it to another computer to read the files.
Th OS does not matter; if you want to protect the data on your hard drive you must encrypt it.