You can not remove the thread just because you have your answer.  It is there for others to read so they can find an answer if they have a similar problem.

 

You could ask the Moderators to remove it but I am doubtful if they will.

You can't even edit your own posts on these boards (actually, there is a tiny 5 minute window since the initial post which lets you edit typos and the like), let alone delete them; as Lyndal said, you're better off asking a moderator to have it removed.