My company has an open license agreement with MIcrosoft. I purchase both a license for Word 2010 and Excel 2010. The system I need to put the software on actually requires Word 2003 and Excel 2003 (Believe it or not). However, when I use the Volume License media kits to install the software, I am getting a message that the product key is invalid. It was my understanding that you could use the serial # from a newer version on an older installation. According to Microsoft downgrade rights chart, I should be able to use this 2010 license on a 2003 install. Can anyone help or shed some light on this for me?