It may not be new but it is still a a security hole.
No it is not.

And incase you missed my last message. If they boot with a floppy or CD in DOS then is it very possible to alter any file in the windows DIR includeing LOGON.SCR.
No, DOS does not understand NTFS, hence will not be able to see the NT partition at all. If you use FAT the system is inherently insecure, AS MICROSOFT FREELY ADMIT and thus don't recommend you use FAT on your system drive.

Of course if you can boot off a CD or floppy full access is easily obtainable anyway, but I won't tell you how because you're a lamer.

PS thanx for the NEG Points
If you want to post up inaccurate duplicate out of date info, you should expect more

Slarty