First, it's the Excel version, not the operating system which determines the
file format. From the info provided, we assume you have Excel 2007 on your
Vista machine, and Excel 2003 on your XP computer. If so, your choices a

1. In Excel 2007, use Save As... and save as Excel 97-2003 Workbook. This
file can then be opened in 2003.

2. For Excel 2003, download the Excel 2007 viewer, available from the
Microsoft website.

Regards,
Fred.

"JLS7" wrote in message
...
I saved an Excel worrksheet on my laptop which runs on Vista. I then
emailed
the file to my home computer which runs on Windows XP. When I try to open
the worksheet on the home computer it get an error message which says
"This
file is not in a recongnizable format" I've downloaded a number of
Microsoft
updates, but they have not helped - I still get the same error message.
Any
help would be appreciated.