NetVault Backup 10 uses the PostgreSQL database. If the PostgreSQL database won't start than NetVault Backup 10 won't be able to start. Trying to start the netvault-pgsql service fails and in the Windows Event Viewer in the application log there will be an error similar to this:
2014-03-13 16:05:32 PDT FATAL: lock file "postmaster.pid" already exists
2014-03-13 16:05:32 PDT HINT: Is another postmaster (PID 1316) running in data directory "C:/Program Files (x86)/Quest Software/NetVault Backup/db/pgsql"?
Delete the postmaster.pid file in the location referenced in the application log and reboot the NetVault Backup server.