So, I stumbled across this question today (https://gaming.stackexchange.com/questions/137676/magic-launcher-wont-log-in). I see there is a comment answering the question in full detail. Is it at all unethical to copy what the user said (putting it into my own words of course) and put it down as an answer? Should I wait for the commenting user to do so themselves before attempting to answer using his information?
As Ashley Nunn said, the community generally doesn't like people who take credit for other's work. However there are still some things you can do:
If the question is answered in the comments, and the OP confirms that the comments answer the question, I usually prompt the commenters to add it as an answer.
If, after a couple of days the question is still unanswered, write an answer attributing the commenters, and mark the answer as community wiki. This way you're not earning rep for other people's work.
However, if you plan to add additional info which isnt addressed in the comments, then the answer is all yours. You should still attribute the original commenters if you're reinforcing one of their points. This answer is an example of this.