HP zpbook laptop, Ubuntu 22.4 installed on master SSD hard drive,windows 10 on a slave HDD. when I choose windows, it provides a message saying 'error: not a valid root device." When I choose Ubuntu works fine. Quoteing from Grub cannot boot Windows: "error: not a valid root device"
Peculiarity. There is one thing that happens that I think is rather odd. Let's discuss three situations: 1- When I turn my pc on, wait for grub to appear and select Windows, the error occurs. 2- When I turn my pc on, enter the boot menu and select 'UEFI - Windows Boot Manager', I do boot into Windows. 3- When I turn my pc on, enter the boot menu, select 'UEFI - Ubuntu' and then select Windows in grub, it also boots to Windows.
Adding to it, I disabled fast boot from bios then opened windows then get it back to fast boot , after that windows did some disk scan and solved the issue and works fine for several times but without changing anything I got the same issue I tried solution mentioned at the link above by disabled fast boot from windows but didn't work Also disabled Hibernation but the same Tried update-grub and
sudo nano /etc/default/grub
add this and save quit
GRUB_DISABLE_OS_PROBER=false
then install os prober
sudo apt install os-prober
then finally
grub-mkconfig -o /boot/grub/grub.cfg
Legacy support and secure boot disabled At bios
