I decide not to do... 与 I don't decide to do... 意思不同：前者否定不式，后者否定谓语动词。比较：

I decide not to marry her. 我决定不娶她。

I don't decide to do marry her. 我还没决定和她结婚。

至于like，道理也一样。虽然我们通常是说 don’t like to do，很少见到 like not to do 的用例，但 would not like to do与would like not to do却是常见的。请看《柯林斯英语语法大全》给出的两组比较句和相关说明：

I would not like to be a student. 意思是：他不是学生，也不想做学生。

I would like not to be a student. 意思是：他是学生，但不想做学生。