Since 2007 has decided it wants to be the default, de-register 2007 and
re-register 2003
Close Excel first and On the Windows Taskbar
Start>Run "C:\yourpathto2007\excel.exe" /unregserver
See the space between exe and /unregserver.
Then register 2003
Start>Run "C:\yourpathto2003\excel.exe" /regserver
This process should make Excel 2003 the default for opening files.
You may not have to unregister 2007 first but I err on the side of
caution<g>
Gord Dibben MS Excel MVP