I find myself solving someone's problem step by step through the comments. When I finally find the solution, should I move the final solution to an answer and delete the comment or leave the comment there as well?
There are few things more frustrating —from a site management point of view— than seeing somebody write an short answer as a comment, the OP say "Thanks that worked" and then everybody just walk away.
Various elements in the system (that are there to help other people get help and answer the right things) require that answers go in the answers section. So somebody should transpose that to an answer; ideally the person who posted it as a comment, but the person who asked the question, or anybody else would do just fine.
If you think you have an answer, post it as an answer. Assuming the question is otherwise good (not obviously duplicate, off-topic, etc), the only questions you need to ask yourself are:
- Is it relevant to their problem?
- Does it attempt to fix their problem (if applicable, not everything can be fixed) or explain it?
There will always be some grey between diagnosis and solution but an honest attempt to fix somebody's problem shouldn't be penalised.
People often get stuck on who should be transposing answer-comments as answers. It's such a British thing, holding a door open for somebody and arguing for 20 minutes over who should walk through it first. The problem is the system really doesn't care about manners and while you're waiting for the original poster to do the right thing, this question and potential answer languish.
Of course attribution is still a requisite here.
If your family couldn't bear the dishonour and social disgrace from you actually being remunerated for somebody else's work, you can post answers as a community wiki. It'll be your name on it, but you won't earn any rep.
You should move the comments to an answer. Comments are considered second class on SE.
Once you post an answer, the comments may be deleted by both of you by moving additional information from OP into the question and your solution to an answer, or can be left around for context. I consider it purely a matter of preference.
Maybe you should consider to gather the info ( in the comments ) you need for the answers and when you spot the solution, then post an answer. This is why the OP has to select the best answer from all answers, don't be afraid and take a stab at it next time.
Troubleshooting is an answer too, it points to a solution because we are not Wizards either. I say you post the answer and leave the comments so people can also up-vote your comments.
Hunt that Yeti, oh great intergalactic Llama!! :P