con ie 6.0:
Mozilla/4.0 (compatible; MSIE 6.0; Windows 98; adsl03)
Win32
4.0 (compatible; MSIE 6.0; Windows 98; adsl03)

con mozilla 1.4:
Mozilla/5.0 (Windows; U; Win98; it-IT; rv:1.4) Gecko/20030624
Win32
5.0 (Windows; it-IT)

il mio os è windows 98se