If you purchased a new motherboard it should have come with a disc with the drivers needed for it.
If you are planning to use a hdd which has a Windows operating system installed with the old motherboard you may have a problem.
The chipset of the motherboard contains identifiers which are Windows recognizes the first time the operating system is started and will continue to recognize these each time the computer is started. If you take that motherboard out and install another Windows will see different identifiers and may not even boot. If it does this doesn't mean that you have dodged the bullet as the system will begin to degenerate and eventually fail in most cases.
If you ever want to move a hdd to another motherboard in the future use the instructions below.
If you run sysprep on the hdd with Windows before moving it you should be be able to move it and boot from it on the other computer. You want to remove all hardware identifiers from the hdd, this generalizes the drive.
Click on the Start orb, then type cmd in the Search box.
cmd will appear under Programs above the search box, right click on it and choose Run as administrator.
This will open the Elevated Command Prompt.
In the Elevated Command Prompt type in CD C:\Windows\System32\Sysprep, then
use the command: "sysprep /generalize /oobe /shutdown"
Don't power the drive back on until it's in the other computer.
Note: You'll want to install matching chipset drivers, video drivers, etc.. after moving the drive.