If you want to restore the MBR system backup, you need to boot in legacy mode. Have a look at
https://wiki.mageia.org/en/Installing_o ... boot_mediaBut as you seem to be running installer to install a fresh system, why do you want to install a legacy system ? If you have filesystem backups,
simply do a fresh installation and afterwards selectively restore your files.
You may want to add some more details on what you want to restore in particular, and what your backup consists or, or what tool you used for the backup.