How to reboot into Windows from Ubuntu?

Question

I'm looking for a way to reboot into Windows from Ubuntu on a 10.10/Vista dual boot system. The specific use case is that I would like to be able to ssh into my running Ubuntu instance and issue a command that will initiate a reboot directly into Windows.

I found a promising blog post, but the script that it suggests isn't working:

#!/bin/bash

WINDOWS_ENTRY=`grep menuentry /boot/grub/grub.cfg  | grep --line-number Windows`
MENU_NUMBER=$(( `echo $WINDOWS_ENTRY | sed -e "s/:.*//"` - 1 ))
sudo grub-reboot $MENU_NUMBER
sudo reboot

man grub-reboot isn't much help, but it seems to be leading me in the right direction:

set the default boot entry for GRUB, for the next boot only

WINDOWS_ENTRY=`grep menuentry /boot/grub/grub.cfg  | grep --line-number Windows`
MENU_NUMBER=$(( `echo $WINDOWS_ENTRY | sed -e "s/:.*//"` - 1 ))
echo $MENU_NUMBER

This returns the expected value, but on reboot the first menu entry is still highlighted. Any ideas why this isn't working or suggestions for other solutions?

Solution 1

• You have to edit your grub first.

  sudo gedit /etc/default/grub
  

• Search for the line GRUB_DEFAULT=0 and modify it to GRUB_DEFAULT=saved

• Update your grub using the following command.

  sudo update-grub  
  

• Now create a script file,

  sudo gedit switch-to-windows.sh
  

• Then add these lines.

  #!/bin/bash
  WINDOWS_ENTRY=`grep menuentry /boot/grub/grub.cfg  | grep --line-number Windows`
  MENU_NUMBER=$(( `echo $WINDOWS_ENTRY | sed -e "s/:.*//"` - 1 ))
  sudo grub-reboot $MENU_NUMBER
  sudo reboot
  

• Make the script executable.

  sudo chmod +x switch-to-windows.sh
  

• And now you can run this script from terminal to reboot into windows.

  ./switch-to-windows.sh
  

• Or you can execute the following command in your terminal

  sudo grub-reboot X  
  

• Where X is the menuentry position of the OS you want to restart in from the GRUB menu.(starting with 0 as the first entry)

For Example:

• If this is your grub menu and if you want to boot into windows you should give the value of X as 5.

• sudo grub-reboot 5

  

• You can also create a launcher for the above command,so that double clicking the launcher will reboot into windows.

Solution 2

There is a grub command just to do so, it is grub-reboot.

It seems to only work when you have grub configured to start with the last saved entry. So if you have not already done so, modify /etc/default/grub and set

GRUB_DEFAULT=saved

then update grub configuration file:

sudo update-grub

From now on, at each boot grub will start the last used entry.

Now, if you want to set in advance what should be the system to boot the next time, use

sudo grub-reboot ENTRY

where ENTRY could be a number relative to a menu entry (numbered starting from 0), or an exact menu entry title, for example

sudo grub-reboot "Microsoft Windows XP Professional (on /dev/sda1)"

This command can easily be made available as a launcher

#!/usr/bin/env xdg-open
#
# save as ~/Desktop/reboot-into-windows.desktop
#

[Desktop Entry]
Version=1.0
Type=Application
Terminal=false
Exec=sh -c 'gksu "grub-reboot 2" && gnome-session-save --shutdown-dialog'
Name=Reboot into Windows
Icon=gnome-panel-launcher

but I don't know how it could be integrated into the system menu.

You can obtain the available menu entry title with

sed -n '/menuentry/s/.*\(["'\''].*["'\'']\).*/\1/p' /boot/grub/grub.cfg 

Solution 3

I think I have found an even nicer way for people who want to the same while locally at their pc without ssh.

A solution to reboot into a specific system choosen through a unity launcher was just posted on webupd8. See http://www.webupd8.org/2011/05/custom-unity-launcher-to-reboot-in.html

I know this is not exactly what the question is about but in case someone has a similar question later this might be helpful.

Solution 4

So for me the best was to create following script with grub-reboot command

#!/bin/bash 
WINDOWS_TITLE=$(grep -i 'windows' /boot/grub/grub.cfg|grep "^[^#;]"|cut -d"'" -f2) 
sudo grub-reboot "$WINDOWS_TITLE" 
echo "Your computer will reboot on ${WINDOWS_TITLE} in 3 seconds, press Ctrl+C if you want to abord it"
sleep 3 && sudo reboot

Solution 5

As far as I understood this will not be exactly what you want but I guess pretty close. Just follow the link webupdate article.

View more solutions

Comments

[Andres]

I can get it to work once. After that you have to enter passwords.

[Mandy]

How did you get grub to look like that?

[psusi]

The config file for grub-legacy is menu.lst, not grub.conf. For grub2, it is grub.cfg, but your second command is only for grub-legacy.

[enzotib]

Don't advice to modify boot.cfg, it will be restored at each manual or automatic update-grub. User should modify /etc/default/grub, instead.

[psusi]

@enzotib, since the change is only meant to pertain to the next boot, there is no reason to do it that way.

[enzotib]

you forget that a wrong editing on that file could lead to an unbootable system

[psusi]

@enzotib, not really; one of the beautiful things about grub2 is that you can always recover manually at the prompt. Also the danger of screwing up other parts of the file is a specious argument, and if you get the default line wrong, the worst that happens is that it defaults to the first entry.

[Michael Gundlach]

Whilst this may theoretically answer the question, it would be preferable to include the essential parts of the answer here, and provide the link for reference.

[Diego]

follow up the question above? how can you get grub looking so perty?

[Philippe Gachoud]

Solution is really great, but as I have 14 menu entries with tab before entries, with the title insthead of menu entry number worked better. So you can change your code with #!/bin/bash WINDOWS_TITLE=grep -i 'windows' /boot/grub/grub.cfg|cut -d"'" -f2 sudo grub-reboot "$WINDOWS_TITLE" sudo reboot

[honi]

Philippe Gachoud, please make yours an answer! it is the only one that works!

[mook765]

There is no reason to set GRUB_DEFAULT=saved, it would mess up your configuration. What grub-reboot does is to write next_entry=ENTRY to /boot/grub/grubenv. That's not saved_entry=ENTRY. Next reboot will be fine though, grub reads next_entry. Following boots may fail if no entry is saved as saved-entry=ENTRY in grubenv.

[mook765]

There is no reason to set GRUB_DEFAULT=saved, it would mess up your configuration. What grub-reboot does is to write next_entry=ENTRY to /boot/grub/grubenv. That's not saved_entry=ENTRY. Next reboot will be fine though, grub reads next_entry. Following boots may fail if no entry is saved as saved-entry=ENTRY in grubenv.

[Xor]

On my Ubuntu 20.04 system there are lines that contain "menuentry" but aren't menu entries, so MENU_NUMBER wouldn't be correct. I think the WINDOWS_TITLE method, mentioned in another comment, works better now

[lolsky]

For Linux Mint 19.3 (Ubuntu 18.04), I used the same script but replaced WINDOWS_TITLE line with: WINDOWS_ENTRY=$(grep -iE '^menuentry' /boot/grub/grub.cfg | grep -iE --line-number '*' | head -n 1)