http://bugs.winehq.org/show_bug.cgi?id=22521
--- Comment #33 from Hans Leidekker hans@meelstraat.net 2011-05-05 07:30:28 CDT --- Does WINEDLLOVERRIDES=mscorsvw.exe=b winetricks dotnet20sp2 work better?
Setting mscorsvw.exe to builtin should disable the .NET Runtime Optimization Service but I think that may be defeated by winetricks calling the dotnet20 verb before starting the service pack installer, hence the service is already running.