Microsoft's support Knowledge Base contains thousands and thousands of articles describing problems that users may encounter. The articles include detailed instructions for fixing each problem, and I do mean detailed--some of them go on for pages and pages. An ordinary user who reaches one of these solutions may find the instructions impossibly confusing.
That's where Microsoft's new "Fix it" button comes in. On selected Knowledge Base pages (over a hundred so far) users can simply click a button to resolve the problem.