It is not necessary to delete devices from a device pool before you delete that pool; the devices are automatically removed when the pool is deleted.
You cannot delete the All Devices device pool, but you can delete all of the devices in it.
If scheduled jobs are assigned to the deleted device pool, you are prompted to redirect them to another device pool.
To delete a device pool
On the navigation bar, click Devices.
Under Device Pools, select the device pool or pools that you want to delete.
Under General Tasks on the task pane, select Delete.
When prompted, click Yes to delete the device pool.
If scheduled jobs are assigned to the deleted device pool, you are prompted to redirect the jobs to another device pool or stand-alone drive.
Deleting device pools