Programs (OEMs) that create recovery partitions modify the MBR (Master
boot record) to provide the function restore option - backing up the
recovery partition to another drive does not change the MBR modification -
in fact deleting the recovery partition does not remove the modification,
which is why OEMs provide a utility to do so if users desire to recover the
partition space by moving the recovery image to removable media.

A backup utility, such as Acronis will create a recovery partition, modify
the MBR and keep the image current - in addition you can create images on
external media - a must if your recovery partition is located on the
system/boot drive since loss of the drive also means loss of the recovery
partition.