Microsoft might have given a flat out no on numerous occasions, but where there is a will there is a way. That's clearly the feeling for one developer who has managed to port the new Windows Phone 7 Series operating system to the HTC HD2 mobile phone.

The phone, which has been available in the UK since November 2009, has just gone on sale in the US on the T-Mobile network.

The hack, which is presumed to be using a developers code version of the operating system, uses two of the five buttons on HD2 for Start and Back functions. Journalists covering the story predict that that the search button might be later remapped to Home button.

One of the reasons for the HD2 not getting a Windows Phone 7 Series update is down to the button configuration under the screen with Microsoft insisting that all Windows Phone 7 Series handsets come with just three keys: Start, Back and Search.

The news is likely to annoy both Microsoft and HTC as the official launch of the operating system and accompanying handsets hasn't been set.

Currently Microsoft is stating "The Holidays" as the launch window.

HTC has confirmed that it will be a launch partner with at least one handset for the official launch.