Good news for Windows XP users, who up till now have resisted the temptation to upgrade to Windows Vista. Microsoft has confirmed that Windows XP can upgrade to Windows 7 operating system. However, Windows XP user can only purchase the Windows 7 license with product key, but need to perform the clean installation of Windows 7 in order to ‘upgrade’ from Windows XP.

Whatsoever, ability to purchase an ‘upgrade license’ for Windows XP to 7 upgrade path enables end-users to migrate to Windows 7 at lower cost. The cheaper reduced price of Windows 7 upgrade license, especially when considering without having to pay twice (XP to Vista, and then Vista to 7) will probably outweighs the hassle to backup the data, install Windows 7, reinstall programs and restore the data to get Windows 7 running on existing Windows XP machine.

Windows Vista users will enjoy more straightforward upgrade to Windows 7, with “in-place upgrade” support where existing data and programs can be preserved and remained intact after upgrading. However, Microsoft also intends to provide ways to help Windows XP users to upgrade by providing other tools and ways to get through upgrade process, but declines to provide further details on how it intends to simplify the upgrade process.

To further ‘encourage’ Windows XP users to switch to Windows 7, Microsoft also plans to shift Windows XP from mainstream support to extended support on April 14, 2009. Mainstream support delivers free security patches, bug fixes and updates to all system, while extended support delivers security updates to all users, but non-security hotfixes only to companies that have signed Software Assurance or Volume Licensing support contracts with Microsoft.

The decision essentially means that three upgrade models is available for Windows users, depending on the source operating system, namely from Windows XP to Windows 7, Windows Vista to Windows 7 and of course Windows 7 to Windows 7 with Windows Anytime Upgrade, where users can upgrade from lower-end edition of Windows 7 to higher end version. Windows 7 will comes in 6 flavors lineup – Starter, Home Basic, Home Premium, Professional, Enterprise and Ultimate.

Update: Workaround to in-place upgrade Windows XP to Windows 7 via Vista or clean install Windows 7 and transfer XP data with Windows Easy Transfer.