Dual boot ubuntu windows 10 - only boots into ubuntu - no boot selection menu

[yinnxbutu]

This is on a Dell 7010 that started out with windows 7 and was upgraded to windows 10. Several months ago I did a dual boot install of Ubuntu and it worked fine. The menu with the boot choices popped up and I could boot into either windows or Ubuntu. Now something has happened to cause that boot choice menu to not appear and so I cannot boot into windows but it will boot into Ubuntu. I read many posts on this and similar problems and finally ran Boot-Repair and here are the results. I did not do the repair because I wanted to see what you had to say about it. I do know that in the bios screen it show everything being "legacy". I guess it has been that way all along. Any help you be is appreciated. Should I go ahead and let boot-repair try to fix it? Thanks.

https://paste.ubuntu.com/p/VndP5D39xh/

[grahammechanical]

Please clarify:

Now something has happened to cause that boot choice menu to not appear and so I cannot boot into windows but it will boot into Ubuntu

Does the boot menu pop up? Or does the system boot into Ubuntu without the boot menu appearing.

In Ubuntu open the terminal and enter this command

sudo update-grub

Watch the printout. Is Windows detected?

Regards

[yinnxbutu]

Yes the menu does not appear, and the machine just boots straight into Ubuntu.

Here is what I got when ran sudo update-grub
https://paste.ubuntu.com/p/gPMr7XnY5h/

[tea for one]

The text below is from your grub configuration

Warning: os-prober will not be executed to detect other bootable partitions.

Therefore, make an edit to /etc/default/grub

sudo nano /etc/default/grub

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT_STYLE=menu # change hidden to menu
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
GRUB_DISABLE_OS_PROBER=false # add this line 

sudo update-grub

Any improvement?

[yinnxbutu]

No change on booting. I did see this though.

mike-OptiPlex-7010:~$ sudo update-grub
Sourcing file `/etc/default/grub'
/usr/sbin/grub-mkconfig: 1: /etc/default/grub: /boot/grub/grub.cfg.: not found

[tea for one]

I'm beginning to suspect that you may have Ubuntu in UEFI mode and Windows in Legacy mode?

Line 230 -  Grub-efi would not be selected by default because legacy Windows detected.
Line 54 - /efi/ubuntu/grubx64.efi /efi/ubuntu/mmx64.efi

Can you allow Ubuntu to load, open a terminal and enter:-

[ -d /sys/firmware/efi ] && echo "UEFI" || echo "Legacy"

What is the output?

[yinnxbutu]

I get this:

mike-OptiPlex-7010:~$ [ -d /sys/firmware/efi ] && echo "UEFI" || echo "Legacy"
Legacy

[tea for one]

When you ran sudo update-grub, did the command find Windows Boot Manager?

[yinnxbutu]

When you ran sudo update-grub, did the command find Windows Boot Manager?

No sign of Windows. Here is what I get:

mike-OptiPlex-7010:~$ sudo update-grub
[sudo] password for mike: 
Sourcing file `/etc/default/grub'
/usr/sbin/grub-mkconfig: 1: /etc/default/grub: /boot/grub/grub.cfg.: not found

[tea for one]

Having identified that both Windows and Ubuntu are installed in Legacy mode, now's the time to run the recommendation from boot-repair (refer to lines 228 - 230).