2008-02-26 Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0) When released, the IE8 beta will introduce an updated User-Agent string. For IE8, we've simply replaced 'MSIE 7.0' with 'MSIE 8.0'. For example, on Windows Vista, IE8 sends: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0)