Can I substitute evaporated milk for regular milk?
Why in heaven's name would you want to? If you mix it with an equal amount of water, you can substitute it for milk in cooking, and depending on the recipe, may or may not notice a difference in flavor. But to us, evaporated milk and evaporated milk mixed with water don't taste very much like milk, so we use evaporated milk only when called for in a recipe.
For a somewhat friendlier answer, check out: Substituting Evaporated Milk for Whole Milk, Take II