http://www.pcworld.com/howto/article...,110663,00.asp
and Microsoft's word on the matter:
http://www.microsoft.com/windowsME/u.../passwords.asp
And Naturally, you can password protect all of your MS office files too. But that doesn't really answer your question of password protecting just ME without going into BIOS. Its a pity you'll have to patch together some semblence of security with ME. Microsoft really didn't provide any.
Then again, even with Windows XP, its unbelievably easy to hijack a password and login with any account with nothing more than a 3.5" Linux boot disk. No windows (or Linux) system is completely secure. At best, you can hold off the amateur users.