If you're swapping out with an identical motherboard, it should work without a hitch. If you're using a new/different motherboard, you will likely be required to re-install Windows. If you're using any OEM version of Windows 7, you will need to purchase a new license as the current license is tied to your motherboard. If you are using any Retail version of Windows 7 or any version of Windows 8 (OEM or Retail), you can re-install without without issue.
-Wolf sends