There are a number of events that lead to Duncan's death in the play.

We first see Duncan in act 1, scene 2. He receives news of the battle: Macbeth has defeated Macdonwald. The Thane of Cawdor is a traitor, so Duncan orders his execution and proclaims Macbeth as the new Thane of Cawdor.

In the next scene, Macbeth and Banquo meet the Witches in the woods. They call Macbeth the Thane of Cawdor and claim he will be "King hereafter." Ross comes and delivers the news that Macbeth is indeed the new Thane of Cawdor. The Witches' prophecies are important because after seeing one come true, Macbeth begins to dream of becoming King.

Macbeth writes a letter to his wife about the prophecies. She then hears the news that Duncan will come stay in their castle, which she sees as the perfect opportunity to dispose of him. She convinces her husband to kill the King.

On his way to do so, Macbeth runs into Banquo and Banquo's son Fleance. This encounter reminds Macbeth of the Witches' prophecy that Banquo's descendants would be kings.

There are many events that lead up to Duncan's death. Narrowing them down to seven will depend on whether you consider a character receiving news to be an event or not. You will also need to decide if you are looking at specific events solely in act 2, scene 1 (as detailed in the other answer) or if you are looking from the start of the play (like my overview above). I hope this helps!

This is too vague a question to answer well. There are seven events in Act 2 Scene 1 leading up to the murder, so I'm guessing that this is the answer you need:

1. The lights are out in heaven (it's the Shakespearean equivalent of a dark and stormy night)

2. Banquo tells Macbeth he's brought a diamond for Lady Macbeth from Duncan to show Duncan's pleasure with them.

3. Macbeth has the veiled conversation with Banquo where he tries to get Banquo to do what he wants but Banquo refuses saying he won't do anything that would be dishonourable or unconscionable.

4. Macbeth tells a servant to ring a bell when his drink is ready (he means when the daggers are out and the guards are drugged)

5. Macbeth sees a dagger pointing the way to Duncan's room.

6. The ringing of a bell...Macbeth says it invites him and it summons Duncan to heaven or hell

7. An owl shrieks...Lady Macbeth calls the owl a fatal bellman

This is what I would call my seven:

1. Witches meet to agree to see Macbeth.

2. Duncan orders that Macbeth take over the title of Thane of Cawdor.

3. Witches meet Macbeth, call him Thane of Cawdor, tell him he will be king and that Banquo will be father of a line of kings.

4. Duncan confirms one of the witches predictions.

5. Lady Macbeth hears of witches predictions. Plots to have Duncan killed when he arrives at Macbeth's castle.

6. When Macbeth returns home, he reluctantly agrees to his wife's plan.

7. Before Macbeth does the deed, he sees a dagger before him.