Any idea how to reinstall Office 2011 for Mac when tech support tells you that the product key you have is not valid (which is also displayed when I try to reinstall it, so helpful!) and I am told there is no way to get the correct product key. I currently have the original box, original receipt, pin, etc. The product key worked the first time I installed the product however it does not work when I try to reinstall it. Currently I have $127.00 worth of a paperweight. Help, please.