This must be done from the server where your database is located. Connect the backup device (e.g. USB flash drive) into your computer. It would then be recognized as the available drive in My Computer and assigned a drive letter, usually D:. It can be different if the computer has multiple hard drives installed.
The backup software will copy two folders to your flash drive:
What needs to be backed up?
You should try to make sure nobody is using the program during a backup, but you don't need to close the program.
Restore your backup to your home computer to make sure it's a good backup. You will have already installed Open Dental on that computer. The version should be the same as your office computer. Verify versions from Help, Update.
If you have trouble opening the program after restoring, you may need to run the setup.exe stored in your backup in the OpenDentImages folder. If the installed version is newer than the backup version, then you will need to uninstall Open Dental from the control panel before running setup.exe.