All card decks
To get all the card decks from the beginning of the game, defeat Voldemort four times.

Getting rid of Peeves curse
When he sets the curse on you, go to the fifth or sixth floor and go to the upper left door. Go through a TV and battle. Once you win, you will get your present back.

Phantom conversation
When going to Snape's Potions Class, note that the Weasley Twins are still in the Common Room. Press Start and walk to where they where standing. Press A and you will be talking to them, even though they are not there.

Find rare Witches 'n Wizard cards
At platform 9 and 3 quarters go to the back of the last lamp post to the left and press A. It's a rare card every time!

117 Sicles
When you are playing go to the 4th floor and find the statue of the old man. Press A by him and you will get 117 Sicles.

Easy House Points
When you have to get the ingredients for snape go down to Hagrids hut. Then go up up to the greenhouses and talk to prof. Sprout. keep on fighting battles and after each one go and see prof. Sprout. When she gives you a house point go back to hagrids hut and the back to prof. Sprout. Keep on doing this and talk to prof. Sprout each time and she will give you a house point each time too.

Finding the stolen presents
When it's christmas peeves will take your presents. To find them go to the sixth floor and go into the room where the door doesn't creak. Go along this corridor and go through the next door. Check the chests and you should find your presents.

Getting the password for Griffindor
When you have to get the password for griffindor go to the 6th floor and talk to the ghost.Then go to the ground floor and talk to the moving monkey statues. Do this to both and you should get the old school tie. Go back to the 6th floor and talk to the ghost again. He will give you the griffindor password.

Catching the purple rabbit
To catch the purple rabbit that Professor McGonagal sent you to do, go outside of Hogwarts. Walk to the left and right next to the first greenhouse. You will see the purple rabbit. In order to catch it, you first have to fight it.

Getting the Rare Harry Potter Card
Complete the game and get more house points than any other house and dumbledore will give you the rare harry potter card.