Windows 7 is a new operating system of Microsoft Windows family. As expected, many existing Windows XP and Vista users would like to upgrade to Windows 7. Both XP and Vista users can upgrade to new Windows 7 provided: their computer meet minimum Windows 7 system requirements or confirm on same using Windows 7 Upgrade Advisor tool.
XP to Windows 7 upgrade
YES, Windows XP users can upgrade to Windows 7 but they could lose data during this process. XP users need to backup their data (like burning on DVDs, online backup) and then perform clean install on Windows 7.
Also, XP users can still buy Windows 7 Upgrade media and perform clean install using it. So backup and perform clean install to upgrade to Windows 7.
Vista to Windows 7 upgrade
It is all easy for Windows Vista users. They can buy Windows 7 Upgrade media and perform upgrade from Vista to Windows 7 without losing data. However, it is recommended to backup existing data on Vista computer to be on safe side.
You can pre-order Windows 7 and receive huge discount upto 50% or order upgrade or retail copy of Windows 7 using this weblink.