Trouble with Internet explorer

If, browsing Internet, I try to go here:
http://www.telelavoro.rassegna.it/fad/telelav/l1/intro_file/frame.htm
where is a slide show I see slides in non readable manner with all
writings overlapped.
Idem when I try to go here:
http://puntoedu.indire.it/progetto/index.htm
My SO is Windows 98 SE
Browser: IE 6.0
Screen resolution: 1024×768 and 24 bit color.
I have also done Browser Challenge, URL:
http://www.attivissimo.net/bc/pagina01.htm
and I have not get over test 4, Internet connection paralysis.
Regards,

Andrea