Just want to clarify, what if the link on my old thread is already dead, can I create a new thread and post a new download link using the same file host? If I remember, I have seen someone did this before...
Or is that considered as double posting?
I am not a moderator so you should wait for a mods confirmation. But I am bored so I will offer my opinion:
If it is a mega-thread, (a thread containing all or a majority of your posts), then I would believe editing the old post would be called for, (perhaps including a note of when the post was updated). If you are talking about an individual post then they would probably be okay if you deleted it and made a new post with the new links, they might not. Editing the post to remove the old links and add the new would most likely be the most appropriate.
Best of Luck.