A clean install IS the way to go!
No offense yeadon563 (

), but I know without a doubt it is always better to do a clean install because even an expert has trouble removing old drivers and leftover remnants of mobo specific software and settings.
All OS's are not well suited to major hardware changes after being installed with original equipment because they suit themselves to the Equipment in many different ways that are not easily undone or changed. It is very possible that someone can swap mobos or swap a hardrive into another system and have no discernible problems with the upgrade....but 9 times out of 10 you will have undesirable consequences because of it.
Please do a backup of your important data, otherwise you may end up starting from scratch and losing alot of effort and time!