win updates seem to screw up grub2

I have 3 laptops with dual-boot Win 10 and Leap 15. The first time or 2 after clean install of Leap 15, all is well, but after that, any attempt to use SUSE is met with “emergency mode.” Initially after rebooting thru this 3-5 times, I could finally boot Leap. Now I cannot, on any of my systems. I have been using SUSE since 1995. My laptops have intel chips T6570, 5500 and 6700.
I do believe the recent updates of Win 10 have been specifically designed to cause trouble with Grub 2, but maybe that is my paranoia showing.

OK, I thought my hardware was failing. Couldn’t see anything abnormal in /var/log/boot.msg.
I could boot into opensuse after I booted into windows.
Haven’t rebooted since.
My system also has leap 15 and win10.


If using MBR booting you can have problems with Windows install and upgrades. But you should really not see that with EFI booting. Also you must not mix boot modes eith all OS use MBR or they use EFI anything else is Trouble.

In any case Windows should not mess with grub itself but if MBR then it will mess with MBR boot code

What does anyone expect when a Linux installer is allowed to mess with pre-existing MBR code in the first place? Windows is only doing the very same thing the Linux installer was directed to do, which it most likely didn’t need to do. When Grub is not installed to MBR there is nothing there for Windows to mess with. Grub isn’t needed on MBR for booting Linux (unless counting the one bit boot flag, in which case putting it back is too trivial to call “messing with”).

Depends what you put in the MBR if grub then Windows can mess with the grub code and stop Linux booting. If you use generic boot code and install grub to the boot partition then the boot flag is used and Windows can and does change the boot flag. In all cases with MBR boot Windows messes with you. Yes you can repair if you know the secret handshakes but you do have to fix things after major Windows updates/installes.

If you are multibooting, you expect some measure of complication. The difference is the “messing”, the moving of the boot flag bit, can be fixed using a trivial “secret handshake”, from within windows, or DOS, or anything bootable that can modify a partition table, and only occasionally, not as a matter of daily, weekly or monthly routine. There’s no need to find “rescue” media or chroot or modify the boot code block or any other installed code when the MBR code is neutral/generic.

can you be more specific about the “secret handshake?”


Sounds like a fast startup issue. Several Windows 10 updates have enabled fast startup, even if it had previously been disabled. If the computer is completely shut down from Windows 10, fast startup is used, which leaves files in a state grub cannot recognize. If the computer is rebooted from running Windows 10, fast startup is not used, and grub works.

To turn off fast startup, see

It’s just a euphemism for knowing how to use any of the many available tools that can move a boot flag, or lacking such knowledge, getting Google to find and explain.