Question about Grub

[haraldme]

I have installed Kubuntu on a harddisk,where I have windows also. But apparently I did something wrong - the system boots only Kubuntu, not Windows. Can I for example install Grub on an USB stick and boot from the stick to have the opportunity to choose, whether I want to start Windows or Kubuntu ? As a newbie, I have no clues .. Thanks !

[claydoh]

Normally, Grub would detect Windows and add a boot menu entry for that.
Are you seeing this menu, or is it booting directly to Kubuntu?

If you are NOT seeing this, try holding down the F4 key after powering on.


Which version of Kubuntu?


At the worst, you should be able to boot to Windows via your computer's specific BIOS/ UEFI firmware boot selection hotkey. Mine is F9, but it can by anything.
Another worst-case scenario is to go into your bios settings and change the boot order.

[Snowhog]

Normally, Grub would detect Windows and add a boot menu entry for that.

Isn't that no longer true? By default now, /etc/grub.d/30_os-prober isn't being executed by /boot/grub/grub.cfg.

[claydoh]

Isn't that no longer true? By default now, /etc/grub.d/30_os-prober isn't being executed by /boot/grub/grub.cfg.

It should be run when Grub is being installed/configured during the OS install, the os-prober being disabled post -install has been a thing for quite a while now.

Unless something has changed again.

[skyfishgoo]

sudo update-grub

pay attention to the output and see if OS_PROBER is going to be run or not.

if not then you need to enable it by editing your

/etc/default/grub

file

[claydoh]

pay attention to the output and see if OS_PROBER is going to be run or not.

I won't be, that has been turned off in grub (post-install) for ages now on most if not all distros.

the system boots only Kubuntu, not Windows.

If you don't see Windows when you do get to the Grub menu, yo can re-enable this:

Add , or remove the "#" in front of the line that has: GRUB_DISABLE_OS_PROBER=false to /etc/default/grub and re-run sudo update-grub if your other OS installs are no being shown in the menu.

While you are there, you might check that the line with GRUB_TIMEOUT_STYLE= is set to read menu

[cookiemuncher]

GRUB_TIMEOUT="-1"

This does not automatically boot into anything and lets you choose.