This option is enabled when setting a schedule for a protection plan. When creating a scheduled task in Windows, Windows asks for your credentials, that is, your User account and password that you used to log in to your computer.


As a best practice, your administrator level account should contain a non-blank password.


When checked, the "Run this plan only when logged on" option allows the software to schedule a backup without the need to prompt for the password that you used to log on to Windows. The software will use the credentials supplied when Windows was started.


You might want to uncheck the "Run this plan only when logged on" option so that you could log off your administrator account when you are not present at your computer. This would help prevent others from accessing your computer and obtaining administrator level privilege (and another reason not to use blank passwords). If a plan is scheduled and the "Run this plan only when logged on" option is unchecked you will receive a confirmation popup, then a popup to enter your password. Enter your password and then click "OK" and then click "Finish" to complete creating or editing the plan.