Hi !
This is not a problem..
I have changed 4 different motherboard with the same windows XP installation, without a problem..
When Xp find a different HW normally stop loading..
You can read this KB from microsoft
hxxp://support.microsoft.com/default.aspx?scid=kb;en-us;824125&Product=win2000
This is dedicated to win2000, but the procedure for win xp is the same..
this is worked fine for me 4 times !!
I hope that is good for you too !!
Bye!