Last month I bought three copies of Office 2007 as I have three systems at my office. I already installed two of them and just trying to install the third one. But one thing went wrong. I forgot to note which two are already installed from the CD case. I thought i could tell by accessing the Product ID, but the ID is not the same as the KEY. Now I wanted to know whether there is any way I can get to know which two of them are installed and which one is left?