Have a close look on Windows® 7 Professional edition
The Windows 7 Professional edition is designed for small business users. It includes all the features of Windows 7 Home Premium, and adds the ability to join in a Windows Server domain.
Windows 7 Professional offers various features that you won't find it in Windows 7 Home and Starter editions. Additional features include features like Remote Desktop server, Windows XP Mode, Network Backup, Offline files, AppLocker, BitLocker to go and ability to join a domain.
Here are the quick review on Windows 7 Professional features.
Windows XP Mode: Windows 7 supports virtualization, so you can run Windows-XP-compatible applications. Windows XP mode will allow you to run your existing applications on Windows 7 system. Windows XP Mode is an add-on for Windows 7 Professional and higher that comes in two parts, each of which has its own setup. The first is Windows Virtual PC, a new version of Microsoft free desktop virtualization platform, and the second is Virtual Windows XP itself, which is a virtual hard drive pre-loaded and licensed with Windows XP Service Pack 3. Windows XP Mode will be available to Windows 7 Professional, Enterprise and Ultimate users.
Backup to network: Doesn’t sound like a big convenience, but beats the pants off having to provide and/or manage plug-in external USB drives when big storage or backup servers are readily available.
Offline files: New enhancements to this capability which controls synchronization between local and network copies of files, especially those that support policies about which ones sync and which ones don’t, may be appealing or convenient for IT professionals but probably not to end users.
Join Windows Domain: Absolutely, positively essential for most corporate or organizational networks. If users want to get any work done on the business network, they must first log in. If they can’t interact with Active Directory.
Remote Desktop Host: A great tool for IT professionals who might need to poke around on, or manage end-user computers remotely. Unless your help desk/IT staff have some kind of analogous third-party toolset, go to My PC, Remote Control Pro, numerous versions of VNC, and so on.
AppLocker: It is a secure, easy to use utility that enables IT professionals to determine exactly what is allowed to run on user desktops. It restricts unauthorized software while allowing applications, installation programs, and scripts that users need.
BitLocker & BitLocker To Go: This tool protects data on systems and provides encryption for removable drives, with manageability to enforce encryption and backup of recovery keys. Windows 7 extends BitLocker protection to USB storage devices while making the original functionality even easier to use.