The HTC HD2 was one of the more solidly built smartphones from the Taiwanese company in recent years back when that was the flagship model which ran on the Windows Mobile operating system. Well, good news for fans of the HD2 as it has been confirmed that the HD3 will run on Windows Phone 7 according to a spreadsheet that you see above. It is being primed to hit the market come this October 18th, where it was named as the HD7. Not too sure what one might make of this, skipping four numbers in the process. Of course, this leaked document is part of O2 UK’s property, so we will wait and see whether more info on a US release is leaked anytime soon or not.