Microsoft has blocked users who have a Windows XP operating system on upgrading to Windows 7 Beta 1 which can be downloaded at their Technet site.
Currently, only users with Windows Vista SP1 can download the upgrade.
We’ve just been telling people like we always do, conduct a clean install. That’s the safest bet anyway. It shouldn’t be too much of a surprise,” said a Microsoft spokesman. If a Windows XP user tries to upgrade, he or she will see a warning which says that upgrading to Windows 7 is not supported.
The article at Channel Web notes that performance decreased from Windows XP to Windows Vista Ultimate to Windows 7 Ultimate on a test that was conducted.
Source: Channel Web

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Lee
only for xp with sp1…. does this meen sp2 and sp3 can’t upgrade to windows 7,,, also what about vista,,, or can do a fresh install any hoo?
thanx in advance for feed back
Only users with Vista SP1 can upgrade. Everyone else has to do a clean install.
That is normal way to do it… It is illogical to be in position to upgrade for 2 versions ahead, simply as there is a lot of changes between XP and Vista. And i see no reason why anyone should comply about that.