Downgrade Licence

• A computer owner running installations of Windows 7 Professional, Windows 7 Ultimate, Windows Vista Business or Windows Vista Ultimate may downgrade the system to Windows XP Professional. Extensions of this program even allow Windows Vista users to downgrade to Windows 98 or Windows 95. Microsoft has no obligation to support a downgraded operating system, so complete the process at your own risk.
  
  

End of Downgrade Rights

• Microsoft plans to end the downgrade rights program for Windows 7 after 18 months of Windows 7 market exposure in April 2011, or the release of Windows 7 Service Pack 1, whichever comes first.
  
  

Manufacturer's Downgrade

• After the release of Windows Vista, Microsoft allowed computer manufacturers to offer the downgrade program as a feature on systems with a pre-installed version of Vista. If you wish to downgrade from Vista and do not have an XP Professional disc, contact your computer's manufacturer to see if your computer is eligible for a downgrade.
  
  

Home Downgrade

• If you own a copy of XP Professional, you may complete the downgrade process without contacting your manufacturer. Since you already have the license for the software on the system undergoing the downgrade, you may use a copy of XP Professional currently in use on another station.
  
  

Other Downgrade Options

• Though it requires the purchase of a new XP Professional installation disc, a clean install of the operating system offers an alternative downgrade option. A clean install clears the data on your hard drive, so back up any important information on your system before installation.
  
  

Undoing a Downgrade

• If at any time you wish to undo the downgrade process, you retain the rights to use the newer operating system by reinstalling it over XP Professional. As long as only one of the operating systems is in use, you may choose between them. If you choose to reinstall the newer operating system, you no longer have the right to use the copy of XP Professional.