Background

• Linux Version: Debian 8.6 Jessie

When setting up desktop or laptop for dual boot into either Windows or Debian, grub2 is typically installed and default to boot into Debian.
For my laptop, I would like to boot to Windows by default.

Resolutions

This can be achieved by modifying the default option GRUB_DEFAULT=0 in /etc/default/grub.

1. Start laptop and desktop to grub boot menu
2. Check the required boot entry (Windows) sequence number on the menu – note the first entry has sequence 0
3. Boot into Debian
4. Edit GRUB_DEFAULT in /etc/default/grub with the target sequence number.
5. Run update-grub – sudo is required if you are not logon as root user.

References

• GNU GRUB Manual – 5.1 Simple configuration handling