PDM (PIX Device Manager) is supported only on PIX Software versions 6.0.1 and later and ASDM (Adaptive Security Manager) is supported on PIX operating on software code 7.x and later. They provide a graphical user interface for managing the PIX Firewall.
There are circumstances wherein administrators might want to disable access to PDM / ASDM for security reasons.
Note: The "no http server enable" command only disables the HTTP server (PDM or ASDM) running on PIX Firewall and does not remove PDM / ASDM related configurations on PIX. To remove configurations related to PDM, use the clear http command and to remove configurations related to ASDM, use the clear configure http command.