When I read this question (which is in the hot network list as I'm writing this question), my first reaction was that it was off-topic, and should be on SuperUser.
Yet, I saw that the highest voted answer to this question was by a moderator, who clearly does not agree with me that this is a SuperUser question. Ultimately, the question is "how do I recover a file from a computer that has been infected by a virus" - which has nothing to do with the fact that the file is a Skyrim game save.
I understand that technical issues (like crash issues) would be considered on topic in some situations, specifically, when the question is really about that particular game. Can someone clarify for me why the linked question is on topic? More generally, what are the rules for the SuperUser / Arqade overlap questions? Which ones should be migrated, which shouldn't, and why?