If you are brave enough to use Inventor 2008 on the 64-bit version of Windows Vista, do not let Windows Update install the Service Pack 1 for Vista. These two do not like each other apparently…
Several users report that after the installation of Vista SP1 Inventor crashes and does not open files. There is currently no workaround (other than uninstall the SP1). Please note this applies to the 64-bit version only, standard Vista with SP1 works fine.
I have tried this sequence and it seems to work for me: first install Vista 64, then apply its SP1, then install Inventor 2008 and then apply its service packs and hotfixes.
It’s a shame that Autodesk has not tested the Vista SP1 consequences before it was released and pushed by Windows Update to the workstations of all the poor Inventor users. The beta version of SP1 was available long enough for such testing.
NB: Inventor 2009 is not affected by this problem