Dell PowerConnect 8024 User Configuration Manual page 325

Command
boot system {image1 |
image2}
reload
Purpose
Set the image to use as the boot (active) image after the
switch resets. Images on the PC8132/PC8164 are named
active backup
and .
For 8100-series switches, use the following command:
boot system {active | backup}
Reboot the switch to make the new image the active
image.
You are prompted to verify that you want to continue.
Managing Images and Files
325