Have installed 2015 and it show installed under "Program Files" but when I try and run, nothing ever shows.When trying to re-install, the Inventor installation screen displays "Inventor 2015" with a red circle with an X and will not let me select it to install. It seems the other components installed OK and they do appear as desktop icons. Tried doing an uninstall and then re-install with the same results. Running Windows 7 with the latest updates and as near as I can tell the computer hardware meets the minimum requirements. I do currently have Inventor 2012 installed but see nothing during installation of 2015 suggesting any type of conflict with the 2012 installation. Thanks for any and all help. Claude