Dell Update Packages User's Guide

Certain packages, such as those that update the system BIOS, require a reboot for the new software to take effect. After you apply an update that requires a reboot, you must restart the system to complete the update.

You have the option of choosing to defer the reboot until another time as long as you do not turn off the system. This feature is primarily intended to allow you to apply any number of updates together and perform the system reboot after the last update has been applied. If this process is interrupted, for example, through a power interruption, you must repeat the updates. Therefore, it is recommended that you schedule updates for a time when the reboot can take place immediately after you apply the last update.