Try booting from a floppy disk (Netware 5 License Disk also has Caldera DOS -> use only a copy!). Copy the needed dos disk drivers, etc. to the floppy.
Make it write-protected.
Then check wheter you can access the Dos Partition. Run a virus scan on it. Then try to manually start \nwserver\server.exe
If You can't access the dos partition, try booting from the Novell CDROM. You can do a reinstall of the DOS partition, just Don't touch the netware partition.
Good Luck!
Alain
regards,
Alain
CCDA/CCNA