Windows 7 Professional is recommended for small and midsize businesses as it provides improved reliability, security, and performance over Windows XP. Key features include Windows XP Mode for running older programs, domain join for simple network access, and location-aware printing. It also offers cost savings over Windows XP and Vista through simplified deployment and new tools. Hardware requirements are 1GB RAM, 16GB storage for 32-bit or 20GB for 64-bit, and a 1GHz processor.