For future note, you cannot do what you ask. What you should have done was go to c:\windows\system32\sysprep and run sysprep.exe, select the Out of box experience (oobe) and checked the generalize tab then selected shutdown. Once shutdown, swap the motheboards then booted it. It would take about 40min to boot up give or take, asked you a few questions and done. Then just install any new
drivers you need and back in business. Your old accounts, software, profiles would all still be there. Just boot up and into your old one, remove the new one your created during first boot and it would look exactly like before, like nothing changed.
As for your outlook issue, open the old PST then drag and drop them into the new one in outlook. Then close the old one.