Windows 7 only has three viable upgrade paths
 

The Windows 7 Upgrade Program is designed to assist Microsoft's OEM partners in minimizing the number of end users who may postpone acquiring a new computer because of the impending release of the Windows 7 operating system. This program allows OEMs to offer an upgrade to Windows 7 to end users who qualify.

# The following are the only valid upgrade paths under the program :
1. Windows Vista® Home Premium -> Windows® 7 Home Premium
2. Windows Vista® Business -> Windows® 7 Professional
3. Windows Vista® Ultimate -> Windows® 7 Ultimate

This is a consumer-oriented program targeted at individual consumers and small businesses that have purchased eligible PCs during the Program Eligibility Period.

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