It's not neccesary to use this " 3-4GB patch " on win7 ultimate 64 ,
just install the game outside "ProgramFiles " example like I do :
" C:\ubisoft\silenthunterIII " .
And I DON'T RUN IT IN " COMPABILITY MODE " it's not useful , it seems if you run it in this comp.mode it blocking something , that silenthunterIII not working proberly
Just install it outside the " ProgramFile " , and it sure work for me . I have 4GB ram on my pc and I have no trouble at all .
regards ,
John