In a mobile computer equipped with Wi-Fi, you can (and should) password-protect operating systems such as Windows XP. This makes it a great deal more difficult (although not always impossible) to boot up your computer without knowing the password.
You can also set a password in the BIOS of most computers. This provides a better level of security than an operating system password, but it is also not absolute.
To set a BIOS password, you must enter the BIOS screens for your computer. This is done during the boot-up process when you've turned the computer on, generally by pressing a key (such as the Delete key) or key combination while the computer is booting up.
For technical information about the security level provided by BIOS passwords, and what is involved in cracking them, see www.heise.de/ct/english/98/08/194/. The article also tells how the author used BIOS password protection as a disciplinary measure with his ten-year-old daughter ("We used to give them a slap on the wrist; now we lock them out of their computer!") and how easy it was for his daughter to circumvent the measure.
I've already mentioned that you should take care to pick a password that can be easily guessed by someone who knows a little about you. In addition, proper password management requires some other steps, including
Choosing passwords that meet certain technical characteristics
Changing passwords on a regular basis
The long and short of this is that as an individual with a Wi-Fi?equipped mobile computer, you should certainly password-protect it before you take it on the road. (Don't forget the password!) But for an organization, there are real costs involved in password protection. These include implementing password management procedures, and also dealing with the inevitable user who loses his password.
In other words, even a seemingly easy security solution like password protection has its costs (at least for an organization). So with any security mechanism, it's worth toting up the value of the data that needs to be protected, and seeing if the trouble is worth it.
If you set a BIOS password, make sure you don't lose it. Despite the various back doors described in the Web reference that I mentioned previously, retrieving a lost BIOS password can be very difficult (and impossible in some cases).
You can easily password-protect your Windows XP computer. To do so, open the User Accounts applet from the Windows Control panel.
In User Accounts, click your logon name. Next, click Create a Password. Enter and confirm your password. You can also provide a password hint if you'd like (this will appear on the Windows welcome screen when your computer boots up).
Click Create Password to accept the new password.