Hi,
'DB restore utility' is to just restore the compressed back file of Lenvica HRMS. if you want to use an old backup file in new Lenvica HRMS version(3.6), just restore the backup file with the restore utility and place the restored ITAS.FDB file in 'Data' folder of 'Lenvica HRMS Installation folder '. By Default the installation folder would be in Program Files/Program Files (x86) of C drive.
Hope this helps.
Rijo