Adding Nightfall Pre-Order/Retail Keys

Yes I used the search function and couldn't find an answer.

Does the order matter in which you add these keys?

IE Pre-Order first then add the Nightfall Retail? Or does it even matter?

I have both and don't want to screw up the pre-order key.

Thanks in advance for your replies!

If you own Prophecies/Factions game it doesn't matter which way you load them, as long as you load them using the "[]manage access key". If you only have Nightfall you'll want to activate NF first.

I don't think it matters, but to be safe, I entered the pre-order key first, then the retail key. I like order.