Netscape FTP directory at HTML World:
(ftp://www.htmlworld.ee/pub/software/windows/Netscape)

Netscape Navigator 1.22 (16-bit)
Netscape Navigator 2.02 (16-bit)
Netscape Navigator 3.04 (16-bit)

Netscape Navigator 2.02 (32-bit)
Netscape Communicator 4.06 (32-bit)
Netscape Communicator 4.07 (32-bit)
Netscape Communicator 4.50 (32-bit)

+ much more

(newest and quickiest downloads at Tucows)
(or directly from Netscape)

Internet Explorer FTP directory at HTML World:
(ftp://www.htmlworld.ee/pub/software/windows/MSIE/)

Internet Explorer 3.02 (32-bit)
Internet Explorer 4.01 with SP1 (32-bit)

+ much more

(newest and quickiest downloads at Tucows)

Internet stuff directory at HTML World:
(ftp://www.htmlworld.ee/pub/software/windows/
(or directly from Microsoft)