Windows 7 Professional: 
 
More Power for Advanced Users
Introducing Windows 7 Professional: More Features, More Capabilities for Business and Advanced Use
Windows 7 Professional addresses users who need more from an operating system with advanced facilities for productivity at work and in business. It includes everything in Windows 7 Home Premium but adds further features for professional use.
 
Why Windows 7 Professional?
It provides more features than XP or Vista and thus targets small businesses, professionals, and power users in search of fine control over their computing environment and larger security. 
Key Features:
Domain Join: Connectivity to corporate networks with the domain-join feature at your fingertips. 
BitLocker: Protect sensitive data through hard drive encryption with BitLocker. 
Remote Desktop: This shall enable one to access your PC from any other place, even from a distant location quite apt, when you work remotely.
Windows XP Mode: This OS allows you to run older applications, which were designed for Windows XP, right from your Windows 7 Professional. 
Advanced Backup and Restore: You can create complete system backups with this operating system and in case something goes wrong you can restore the files in a very easy way. System Requirements:
 
Processor: 1 GHz or higher-32-bit/64-bit processor
RAM: 1 GB RAM
Hard Disk Space: 16 GB available hard disk space 
Graphics: DirectX 9 graphics device with WDDM 1.0 or higher driver
Display: 800 x 600 resolution
Best Suited for:
Business Usage: It offers functionality to manipulate and control your business environment.
Power Users: Mainly for those kind of users which require more utilities and even more security.