GRUB does not see other OSes

Starting with Sparky 7.0 “Orion Belt”, the default configuration of GRUB bootloader does not “see” other operating systems as default.

To fix that do:https://wiki.sparkylinux.org/doku.php/grub_does_not_see_other_oses?do=edit

If the grub config file does not exist, copy it, as root: 

sudo cp /etc/default/grub.ucf-dist /etc/dafault/grub

Then edit it, as root, using any text editor, for example nano: 

sudo nano /etc/default/grub

adding the following line: 

GRUB_DISABLE_OS_PROBER=false

on the end of the file.

Then update grub: 

sudo update-grub