The last Excel version to support the DB3 format was Excel 2003. If you have that or an earlier version, you can run both on the same PC (but you don have to install the older one first). Alternatively, there are products that appear to work with Office 2007 (at least). See, for example:
http://xdbf.com/excel-2007-converter.html
http://download.cnet.com/DBF-to-XLS-...-10405779.html
http://www.brothersoft.com/xls-to-db...ter-71739.html