if it's outlook and not outlook express then find the file called outlook.pst, normally in:
c:\documents and settings\local settings\application data\microsoft\outlook\
and copy it into the same location on the new pc. if it's not in this location, (coz it's windoze 98) then go into outlook then FILE --> then data file management to find out the file path. you can always use the export/import tools but you'll achieve the same result.