I'm a hard gainer too but I've been able to break through it. A good tip for you is to make sure you start your day with a good amount of calories, say by 8am. Then if you can force a second meal between 10-11am you should be on your way to a decent caloric intake day. Here's the shake I create daily:
Mix in blender for about 45 sec:
20oz organic skim milk
(2) scoops NOW Whey Protein Isolate - Chocolate
(2) scoops Jiffy Natural Peanut Butter
(1) tablespoon organic cold-pressed extra virgin olive oil
(2) tablespoons organic cold-pressed extra virgin coconut oil
That should put you at a nice 1,015 calories, 75+ grams protein, low in sugar, great mix of poly/mono/healthy saturated fats and I promise you it will be smooth as butter. I can pound it all in less than a minute.
Also, make sure you avoid things that may suppress your appetite such as caffeine, etc.
Good luck.