And/or in a negative sentence

A lot of students seem to be confused about whether to use "and" or "or" in a negative sentence. To make things clear, take a look at the following sentences.

• I like milk and coffee: This is an ambiguous sentence. It could mean that you like having the two together. But it could also mean that you like milk as well as coffee.
  
• I like milk or coffee: This is what you would say when asked "what do you like to drink in the morning?" You like both of them, but don't really care which one you have.
  
• I don't like milk and coffee: This means you don't like having the two together. But you may like having milk or coffee alone.
  
• I don't like milk or coffee: This means you don't like milk and you don't like coffee either.
  

The point is, when there are two or more items, and you want to negate all of them, you should use "or," NOT "and."