There has been a tizzy brewing this week over the fact that Microsoft will allow users to downgrade Windows 7 to Windows XP well into 2010. The Mac zealots are abusing the discovery to extol the superiority of OS X and the Linux users are seeing it as an indictment of Windows 7 and a herald for the rise of Linux.

Newsflash: It’s nothing new.

In fact, the OS downgrade right is a continuation of a long-standing Microsoft policy written into the agreement for volume license customers like OEMs and the enterprise. Anyone with the green to purchase a massive block of keys is given some latitude to match the installed OS to the standard design of their network.

The Microsoft Volume Use License Brief (DOC) explains:

Downgrade rights in the Volume Licensing programs provide customers with the right to downgrade to any prior version of the same product. Windows Vista Enterprise is a new type of product and does not have a prior version. However, customers licensed for use of Windows Vista Enterprise are licensed for Windows Vista Business, and it can be downgraded to the Windows XP Professional, Windows 2000 Professional, Windows NT® 4.0, Windows NT 3.51, Windows 98, or Windows 95 operating system.

Corporations cannot waste time trialing an OS that differs from their standard image, so Microsoft has always given these buyers (and their OEMs) the ability to downgrade an OS to suit. It’s right in the contract, and Microsoft has echoed its terms when queried for clarification

“This is not the first time that Microsoft has offered downgrade rights to a version other than its immediate predecessor and our volume-license customers can always downgrade to any previous version of Windows,” said a Microsoft spokesperson.

Windows XP is the most common Microsoft OS. Millions of corporate users run it. Replacement PCs must match the installed and tested platform. It would be commercial suicide for Microsoft to block downgrades, and we hope everyone can get over this FUD and move on to legitimate stories.