A certain user is being a general pain, and aside from me reporting the user (which I have done) how else can I prevent them from contacting me?
The system currently does not allow you to block a user. When you see a rude or offensive comment, please flag it as such. If there is repeated offensive behavior by a certain user, we will check it out.
In the particular example, you flagged the following comment as rude:
This doesn't explain how to solve the problem. This just indicates you had a entirely different problem, and you gave up, and installed Windows 10.
I don't see how it is rude though. Granted, it is very direct.
But remind you that your answer was downvoted four times—so there's more than one person who thinks that it is not helpful. The user was just giving you a reason for the downvotes. I have the feeling that in this case, it looks more like trying to shoot the messenger.
I find your response insulting. […] Find something decent to say next time. If you can criticise my answers, then provide a better answer. […]
And that's basically setting the stage for a comment thread where people actually insult each other—as we see so often on Super User.
But the other user did not give into that and explained what they meant. I've read the thread a few times now, and none of the other user's comments are in any way personally insulting. They just explain a potential downvote.
In the future I'd advise you to walk away from comments (and flag them) if you believe you're personally attacked. Let the rest be handled by the moderation team.