Faith, the problem has certainly nothing to do with German Windows; there's no difference in Chest operations between various language versions of the OS, so the problem must be somewhere else.
Could you please write your last message in German? I'm afraid I don't understand what you are trying to say, and I would like to know how exactly you did the scan (I think I'll understand better in German). Thanks!
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Guys, the two options you are talking about are closely connected. The one on the first page enables scanning of DLLs, the one on the second page makes avast! ignore some of them (in particular, the trusted - system - ones). So, the first one makes avast! scan more, perhaps slowing the system a little, the second one should, on contrary, make it faster (when checked).