compatibility

Is it possible to backup a complete opensuse system and
extract it on another different machine ?
I do explain. I’ve an opensuse system at home, I would like
to copy the exact system on a notebook.
I’ve a full home system backup ( I did with dar in live cd )
Now, if a just extract it on a clean notebook partition,
change /etc/fstab pointing, linking them to new partitions, change
/boot/grub/menu.lst, install grub, and eventually create a new
initrd with mkinitrd, does the notebook opensuse new system starts
and works ???

Probably not unless the two machines have identical hardware because part of the installation process involves installing the software to match the hardware.

Unless you have made significant changes to your system files, you will probably find it easier to do a fresh install on the other machine and then copy over /home. All your personal settings are in /home unlike in Windows.