Well...you're not supposed to be able to but I'll bet that one of the gurus over at xda-developers.com will figure out a way to cook a WM7 rom in no time...

>You can't. There is no upgrade path from 6.x to 7.
>
>>You have the t-mobile version? I have the HTC HD2 & was thinking of getting an HD7. The specs seem almost identical - I might try to put WM7 on my HD2...