This is asking for trouble; comments are a problematic way to store answers, as they...
- ...can't be edited
- ...can't be downvoted
- ...can't be searched for
- ...can't be accepted (thus marking the question as answered)
- ...don't mark a question as answered even when heavily upvoted
- ...can be deleted rather easily
- ...always display in chronological order
- ...do little to prevent the question itself from being deleted (by the author or others)
- ...are a pain to read for anything non-trivial
Best course of action when you find one of these questions is to... Post an answer. Take whatever information is in the comments, and put it in an actual answer. Then if that answer proves useful, it can be upvoted or accepted (which marks the question answered), in addition to addressing all the other deficiencies present in the list above.
Best part? You don't need to be a moderator to do this; literally anyone can take this step, including people who don't even have accounts.