The NFTS file encyption capabilty and the system restore functions are sufficient reason for choosing the Pro version. Ordinary users may think that they have nothing in their machines to make hacking their machines worthwhile; actually every user has what hackers most value - storage space and an address book. Improved security and the ability to get a compromised machine back to where it was before, are well worth paying a premium for. Of course an IBM machine comes with IBM's own file encryption and restore functions embedded leaving no need to go for the XP Pro version, but most people use clones...