Start Excel 2003, and then use the File-Open dialog to open your
spreadsheet file.

When you installed the Office 2007 trial version, you were given the
option to either keep your existing Office version alongside the trial
version, or to replace the existing Office version with the trial
version. If you chose to replace the existing Office version, then
you'll need to reinstall the existing version from your Office CD.

Stormingerman wrote:

I installed trial version of Excel 2007 yesterday (because I needed Access
for another project). When I opened an existing Excel document it opened in
2007 but many functionalities are deactivated, meaning my entire inventory of
Excel workbooks are dead (?) MSFT says buy 2007. I am not ready after 24 hrs.
How do I open existing xl sheets in 2003 version?