Another disappointment was not being able to upgrade from xp directly to 7
My assumption to this is that they supported the direct upgrade to Vista as it was the next Windows Version in line, but now that Main Stream support for XP ended in April of 09, (You can get extended and pay for support for XP, but not general open support for XP), they remove the option, to not have to field those calls. Understandably, in my opinion.
Note, that MS are on a 5 year Main Stream Support Lifecycle
and really always has been.
XP became an exception to this due to several factors. SP 2 and 3 Development slowed the development of Longhorn (Vista), the ending of Longhorn version 1 and restarting the development played a large role in XP lasting for so long, which it was never meant to do.
Which is why we will probably see Windows 8 about 2012 -/+ or 2013. This is a guess, but should be about right. Some say 2011, some 2014. Unless something goes wrong.
To the original poster....... I would also recommend a clean install. Swapping Mobo's even if you can do a repair install, will not remove any potential conflicts of Drivers, etc.
Chipset drivers, etc. A reapir install is NOT going to remove existing drivers, and registry entries pointing to those drivers. Running Driver updates, may also not change these pointers. Conflicts are a very real possibility no matter how well you think the swap went.