It sounds like you may be encountering an issue with Word 2008 trying to import preferences from an older version of Word (2004 or v.X perhaps?).
Our MVP's have put together a quick list of possible solutions at:
<http://word.mvps.org/Mac/Word2008Issues.html#LaunchCrash>
The following KB article also lists methods that may resolve the issue categorized by what previous versions of Office you may have installed. <http://support.microsoft.com/kb/948489>
Please let us know if this helps. And thanks for giving the trial a shot!
Best,
Marshall