You've somehow managed to trash the contents of the HD, hence the DH0:NDOS... (most likely the RDB)...
You'll need HDtoolbox or HDinstalltools from your Workbench disks (if you have them). Best thing to do would be to firstly try reinstalling the RDB with HDInstalltools and see if you can get it working from there, that way you may be able to recover some data/files that you may already have on the HD.
Failing that it looks like you'll need to do a complete repartitioning and quick format of the HD using HDtoolbox and then re-install Workbench 3.x, but this will lose any data/files you may have on the HD that you might be wanting to try and recover...