here
http://technet.microsoft.com/en-us/library/dd772579%28WS.10%29.aspx
what it says is you'll need is the Windows 7 Anytime Upgrade product.
Can I upgrade Windows 7 home premium to Professional using a disk labeled "Upgrade designed for Windows Vista" ??
I bought a new Sony laptop with Win.7 home premium on it and I bought an upgrade disk to Professional labeled "Upgrade designed for Windows Vista"
Will this work ok? So far I have not installed any programs.
I want to be able to install "XP mode" and home premium will not work.

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