With the end of Windows XP coming on April 8, 2014, the recommendation to many of my clients is to upgrade to Windows 7 Pro. However, before purchasing an upgrade license and going through the upgrade process, it is important to first check your computer hardware to see if it will actually support Windows 7 Pro.
The easiest way to do this is download Microsoft's Windows 7 Upgrade Advisor. This application will check for compatability issues.
You can download it via this link: Download Windows 7 Upgrade Advisor