Game fails to load

Could somebody please give advice on problem? After getting so far in Dungeon
siege ll the game won't load fully anymore it stops half way I have had this
problem previously and I have done any & everything suggested to fix the
problem. However I have found that it wont load any of the saves we have but
it will load if i start a new account in xp and start a new game does anyone
know why this is happening? we are sick of starting from the beginning all
the time.
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Cheers sutyjeba