External table is not in the expected format Error for .xls files

Hi

Is the xls file encrypted with a password?

Or if the file was saved in xlsx format then use the ACE driver.

There is more information in these articles

http://support.smartbear.com/viewarticle/28747/

http://support.smartbear.com/viewarticle/33282/

If the ExcelDriver works with any other xls files (not downloaded) then there may be a problem with the format of the downloaded file.

Are you able to open the file in Excel then use the Save As command to confirm that "Save as type" is the Excel workbook format?

The cause of the error seems to be similar to

http://blog.crmguru.co.uk/2010/07/01/annoying-file-format-warning-when-exporting-crm-records-to-excel/

The XML file format differs from the XLS extension so you could use the save as command in Excel to convert the file format, or some other conversion tool if it is an ongoing problem.