The HTC HD2 not only can run on Android (even Gingerbread), it can run also on Windows Phone 7.To be more specific, it can actually support Windows Phone 7-Android dual-boot, something that would certainly offer those enthusiasts out there some reasons to rejoice.It’s not easy or pretty, but Darrengladysz from XDA-developers has put up a tutorial on how to run both OSes at the same time.
In order to make your HTC HD2 have both Windows Phone 7 and Android available for boot, you would have to install the OSes on the same microSD memory card, in a process that is described on XDA-Developers forum here.
Two cards would be required in the beginning, one on which to put bot OSes, and another one to create a partition for the Windows Phone 7 platform, it seems. One would also need to partition the microSD card, so as to put the two platforms on it.
All of the necessary instructions on the process are available on the aforementioned post on the XDA-Developers forum.
In case your HD2 would seem more appealing with dual-boot capabilities and with the possibility to make it run either Windows Phone 7 or Android, and you want to give this dual-boot option a try, make sure that you read the said instructions carefully, so that things would go as intended.