I flagged to have this removed, as it is completely worthless in just about every conceivable way.
Do crap answers like this make SO better?
Leaving an answer that's wrong (and not merely irrelevant or nonsensical) can be useful: they're a warning, an indication of what doesn't work. It's important that the answer be downvoted, to indicate that it's wrong. Sometimes you'll find that someone posts a wrong answer, then it's deleted… and someone else posts the same wrong answer, and it's deleted… It's also important to explain (in a comment) why the answer is wrong. Since this answer has been downvoted and commented on, it's not actively doing harm, and it's a deterrent to anyone who might suggest the same method again. Having it on the site is not noise.
In addition, moderators cannot always judge the technical accuracy of posts.If the moderator who handled your flag is unfamiliar with the topic of the question, how are they to tell whether installing the interopt assemblies solves the asker's problem? (I, for one, can tell that the post makes a statement that answers the question, simply from basic skills in the English language, but I have no idea whether that statement is true.) So moderators are not supposed to delete wrong (as opposed to irrelevant or nonsensical) answers: judging the technical accuracy of answers is explicitly not in their task description.
No, but it's not the moderators' job to decide on the technical accuracy of answers. Just downvote and - if necessary - comment.