copying only the s/startup-sequence file from an original workbench disk to your s/ directory on the hard drive will most likely enable you to boot up from your harddrive
type this in the dos-shell
copy df0:s/startup-sequence to dh0:s/
note: if this fails and you were bright enough to substitute the standard device names in that command
with the ones you use on your system
i fear that game might have corrupted your harddrive
you didn't by any chance install 'syndicate' did you?