The Microsoft Excel file ‘<Drive\Directory\Filename>’ has no named ranges. Use Microsoft Excel to name the range of data you want to import.
Had an Excel file that I tried to import to Outlook that was throwing this error. First, make sure you have a header row with column titles so you can assign the data to the proper fields in Outlook. Simply select the cells you wish to import (only select the cells with data in them including the header row). Then (for Outlook 2007) click on Formulas –>Name Manager in the Defined Names section and then set a new name (I used “contacts” as the name) and save the file. Then Import on Outlook using “Import From Another Program or File“. Follow the instructions to assign the columns to the proper field in Outlook and that’s it. Good luck!
More info on this process (older info) here: http://support.microsoft.com/kb/180315