You are a network administrator for your company. All servers run Windows Server 2003. A network server named Server1 functions as the main file server. Server1 is backed up each night by using the Backup utility. You perform a test restoration of Server1 by using the Backup utility. You discover that files that are open during the backup process are not being backed up. You need to ensure that open files are backed up successfully. What should you do? （）