I had a emachines laptop for christmas with windows 7. When this was bought we were under the impression that it came with Microsoft office. When i tried to activate Microsoft office and entered the product key(on the microsoft certificate sticker on the back) it keeps saying its invalid. Can anyone tell me if this is this product key for windows (that was pre-installed) and not MS Office? Also if this is the case where is the best and cheapest place to purchase office? Thanks YP