Now that we've looked at some of the methods of recovering a stolen laptop and preventing said laptop from going walkies in the first place, let's turn our attention to some preventative measures you can take to stop your data from being compromised if the worst does happen.

If you've read our recent guide on recovering forgotten passwords from Windows XP (and you really should), you'll already know that it is extremely hard, some would say impossible, to effectively secure a computer to which an intruder has physical access. There are four steps you can take to make it rather frustratingly hard and time consuming for the bad guys to get at your vital data however. Let's take a look:

STEP 1: BIOS password protection

Most modern computers can be password protected by setting a password in the BIOS (Basic Input/Output System) built into the motherboard of the computer. This is a group of settings that govern how the computer manages its hardware, regardless of what operating system it may be using. Changes made to the BIOS are stored in a small area of built-in memory called the CMOS, which is powered by a battery also built into the motherboard.

Now on desktop computers, password protecting the BIOS borders on the completely futile as a security measure. Any intruder can simply open up the case and use a jumper to reset the CMOS, or even just yank out the battery powering it for a few minutes to make sure it (along with the password) is wiped. It's a different story with a laptop however.

Laptop computers are built on proprietary designs, using motherboards created specifically for each model. It is often not possible to get at the CMOS battery of a laptop without special tools and know-how, or at least not without destroying the machine in the process. Generally speaking, if you want to reset the BIOS password on a laptop, you will need to ship it back to the manufacturer, something your average thief is going to be understandably reluctant to do.

This makes BIOS password protection a rather good option for users who are concerned about the possibility of data theft, as a BIOS password makes it impossible to boot into any operating system until it is answered. It's not foolproof, as many manufacturers have built 'backdoor' keystroke combinations into their systems which can bypass even BIOS passwords, but it's a great start.

To set the BIOS password, press the DEL key several times immediately after the POST screen comes up (some manufacturers use a different key stroke, but this should be indicated on your screen during boot-up, or in the manual) to enter the BIOS setup. You are looking for 'set password' or something similar. Set it (write it down so you don't forget it) and save and exit. The next time you boot, you will be prompted for a password after POST.

Make sure you keep a record of the password - but not in your laptop bag please!

STEP 2: Set Really Good user passwords

This speaks for itself. After stealing your laptop, the intruder has all the time he or she can afford in which to crack the password for your administrator account and get full access to your data. Chances are, at some point they will use the SAM and SYSTEM file password hash extraction method (again, as covered in our password recovery article) in combination with some sort of password cracking software to discover your password.

Let's look at what might happen… Say your password was 'rover;' It would take them about 5 minutes or less to crack using a fast computer. Say it's 'rover35' add another 10 minutes maybe… But what if your password was (r0V3r35) You've just extended the time it will take them to crack your password to several hours, perhaps days.