If you keep valuable files on your laptop, you probably know that you ought to protect your data. But knowing you should do something isn't the same as actually doing it, as evidenced by the steady stream of incidents where sensitive information gets lost or stolen from corporate laptops. However, locking down data isn't hard or expensive. We show you how.

The tasks of installing and running encryption software have not always been easy. But encryption is now simpler than it has ever been, with tools such as Steganos Safe Professional 2007 and Bullguard Backup making encryption a simple, but central, part of PC security.

I tried PGP Whole Disk Encryption 9.6 (£95) and SecurStar DriveCrypt Plus Pack (€148.75 inc VAT - that's about £105). Both applications can encrypt single files, batches of documents, or the entire hard drive and everything on it.

This last feature makes the most sense. You enter your password only once per Windows session, and everything gets encrypted automatically as you work.

Files are encrypted only while on the hard drive. If you send an email attachment to someone from your encrypted hard drive, the software automatically decrypts the attachment before it leaves the PC, and the recipient receives a normal, unscrambled message.

Full disk encryption tools used to have one major drawback - they slowed PCs considerably. But as processor power has gone up, software makers have optimised their products so effectively that you can barely tell the encryption is happening.

We surfed the web, checked and sent email, and even played some graphically intensive games on the encrypted laptop without encountering a perceptible performance hit from the encryption software, which quietly went about its business in the background.

With tools like these available, you have to wonder how many laptops full of sensitive information must be stolen from the car trunks and airport lounges of the world before their owners do something to protect that data.