I'm assuming that you have a xbox store download code for your game as part of the combo deal? If so, the code is valid as soon as your register receipt is printed and should work immediately without activating your newly purchased time. However, why not just activate it? All it will do is push out your renewal date by amount of time your bought for the combo special. That way you don't lose your time by misplacing the card you bought. Just my two cents! Have a great day!