Check the Euromillions results to see if you've won. If your Euromillions numbers match the numbers drawn, then you've won the Euromillions jackpot!
You can still win a prize even if you have only matched one number and the two Lucky Star numbers. If you have used an online ticket vendor, such as those here, and have won a Euromillions prize, you will be notified of the results and your winnings will be paid to you directly.
If no players match all of the numbers with the Euromillions results, the jackpot prize is carried over to the next game and added to. When a Euromillions Superdraw takes place, the jackpot is shared between the players with the closest numbers.
Take care of your ticket! Seems obvious, but the fact that there are hundreds of millions left unclaimed, would suggest that perhaps it's not so obvious.