This document explains why you may not be able open a Microsoft Visio 2007 file with an earlier version of Microsoft Visio.
You receive the following message/error when attempting to open a Microsoft Visio 2007 file:
"You have reached this page because the .vsd file that you are trying to open was created in Microsoft Visio 2007. Converters for opening Microsoft Visio 2007 files will be available during the last quarter of 2007. Until then, to open this file using Microsoft Visio 2003, the person who created the file needs to save it to the Microsoft Visio 2000 - 2003 file format."
You will need to to ask the person who sent you this file to save it to Microsoft Visio 2000 - 2003 file format and send it again.
NOTE: Both 2003 and 2007 Visio files end with ".vsd"