Hello... Plug in your OS hardrive and see if it boots to Windows... Sometimes it does. Then all you have to do is un-install your previous MB chipset drivers and install the new ones.
I was successful recently with a P35 Q9550 to Q77 i7 3770... Boot into Windows 7 Pro... just needed the new Chipset MB drivers. Too make things easier on the Booting OS, disable all the LAN, Audio Devices, in the MB BIO's if they are different chips than your OLD MB.