When you bought it at Costco what does the package say? Did you turn it in for the CD at the window? That come with the 16 digit License Code. A lot of people don't realize you have to get the real package. I bought mine from Costco yesterday. Did you buy it in the store or online from Costco? I don't think they sell the online version at all, just the download program online or CD in the store.
If you buy the CD you can use the download method to install it.
