XL2000: Quattro Pro 7.0 (.wb3) Converter Available
(268134) - The Quattro Pro 7.0 Converter for Microsoft Excel 2000 is now
available from Microsoft. The Quattro Pro 7.0 Converter allows Excel 2000 to
open .wb3 files. ... http://support.microsoft.com/kb/268134/en-us
You can try this. If that doesn't work you can use the Save As command in
Quattro Pro to save the files as Excel files and then open them in Excel.
