Windows 7 Professional offers all of the performance and security enhancements that the new operating system brings to bare; Enterprise further enhances those bedrock components through version-specific features.
Within Windows 7 Enterprise, you will find the following features:
Windows XP Mode is a virtual machine package in Windows Virtual PC that comes with a licensed copy of XP SP3 as its guest OS. It allows applications that run in the virtualized environment to appear to the user as if the apps are running directly on the Windows 7 host. XP Mode helps remediate app-to-OS compatibility issues.
DirectAccess is a feature found in Windows 7 Enterprise and Windows Server 2008 R2 that provides a productive work environment for users. It gives mobile workers the ability to be connected to enterprise resources, as long as they have Internet access, without the need for VPN.
Unlike with Windows Vista, the Enterprise and Ultimate editions of Windows 7 will carry the exact same features. The only difference is the name and how the editions are acquired. Enterprise can be acquired through volume licensing as a software assurance benefit and Ultimate can be acquired through OEM and retail markets.
No, you will not be able to perform a direct upgrade. You will have to perform a clean installation. There are tools such as the Windows Easy Transfer that can assist backup and migration of your data, selecting Internet favorites and preparing settings.
Windows 7 Professional offers advanced backup and restore features. You can have your personal files and folders automatically backed up to a network share or external USB drive. In addition, you also have the ability to schedule backups any time of the day.