Click first on 'ok' to select the default wineprefix, then click on 'Install a windows dll', then click on 'dotnet20'. That might let you run the sims3 launcher. But there's a problem: http://bugs.winehq.org/show_bug.cgi?id=26273 Wine can't detect the cd-rom on Linux. A fix for the bug is known, but requires fixing the linux kernel. Jake Ward runs sims3 fine without the fix, but I can't tell you how.
