cannot fsck because root is not read only

During the boot sequence I see the following message on screen. ERROR ! cannot fsck because root is not read only. This started afer using mkinit or mk_init following the removal of a NIC module. That was fixed but since then the ERROR message occurs. How should I restore the normal fsck after 20 boots. /dev/hda5 is the root What is the correct command to make root read only at boot time and restore the normal operation? -- John