What can a low rep user do with an old forgotten duplicate post?

Question

This post is a duplicate of My computer boots to a black screen, what options do I have to fix it? but has not been marked as so.

I could:

1. Answer the question & it should get marked.
2. Down vote the question & it will be deleted it time.
3. Comment to the user to delete the question.
4. Flag it for moderator attention.

I don't want to down vote it just because it's a duplicate question.

What should I do? Should I just leave it alone? I would like advice for future questions.

Answer 1

The correct action to take is to flag it. Click flag and then select "it is a duplicate". Then you can enter the URL of the other post.