Do you want to remotely access your computer so you can work with all your data and applications while away from your desk?
Remote Desktop, a feature found only in Windows XP Professional, lets you set up your computer for connection from any other Windows-based computer. Leave a file at home? Don't want to lug a laptop around? Remote Desktop gives you access to your computer from virtually anywhere. More about Remote Desktop.
Do you connect to a large network?
Windows XP Professional is best for people who connect to large networks, such as a school or office network, since it allows you to join and be managed by a Windows domain. More about joining networks.
Do you need to protect sensitive data in files and folders that are stored on your computer?
The Encrypting File System (EFS), found in Windows XP Professional but not Windows XP Home Edition, allows you to encrypt your files and folders for added security of sensitive data against theft or hackers. Restricted File Access, also found only in Professional, allows you to restrict access to selected files, applications, and other resources. More about EFS.
Do you need the ability to completely restore your system in the event of a catastrophic failure?
Windows XP Professional provides more robust options for backing up and restoring data than Home Edition. More about System Restore and other restore options.
Would you consider yourself a "power user"?
Windows XP Professional contains a number of incremental features too numerous to list here. Suffice it to say, users who demand the most from their computers will want to "go Pro." Some additional features found only in Windows XP Professional are:
Advanced networking for multiple PC environments
Internet Information Services (IIS), a Windows XP Professional feature that lets you host and manage personal Web sites
Support for multiple-processor systems
Support for multiple languages