According to the companies, Windows Vista Ultimate and Business edition are the only versions of Windows that carry the downgrade rights, which allow anyone running either operating system to legally downgrade to Windows XP Professional if they find Vista unbearable.
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XP gets another stay
"Customers may continue to get Windows XP Professional by exercising downgrade rights that come with Windows Vista Business or Windows Vista Ultimate licenses," Dell wrote on the company's site.
"Dell has the ability to exercise 'Windows Vista downgrade rights' on your behalf in the factory if your business is still reliant upon Windows XP and you'd prefer to have Windows XP Professional preinstalled on your PCs."
Microsoft has yet to comment on the decision by Dell and Lenovo, but the company can't be happy that more XP installations will find their way into the wild when it's frantically trying to make Vista more appealing.