That sentence states that you should not buy a license if you have no verified that WinRar will completely function on your computer. It does not state any obligation to purchase the software after the trial is over.
it says that once you know it works on your computer, you must buy a license. the 40 days is an arbitrary (but
very reasonable) time frame that they consider long enough to figure that out, and both a jury and a judge would certainly agree with that. for that matter, anyone who wasn't trying to use software longer than they were allowed to would
I don't know how you can genuinely believe it doesn't say you have to buy it. you can insult everyone who disagrees with you, if you want, but that doesn't make us wrong