I bought office 365 the other day from best buy. I downloaded it and I used word just fine. but when I saved it to the desktop and tried to open the file, it says that I don't have office 365. I can open word and open the file from there, but I want to know why it says that I don't have it....also when it tells me that I don't have it, it gives me the option to say "i already have it" or something like that. when I click it, it tells me to enter the product key and I do. when it takes me to the page it takes me to, it says that I already used one of my installs. so any idea what's going on?