It is a couple of years ago - pre-UEFI times - when there repeatedly were users on this forum asking for help because their windows updates or service packs wouldn't work after they had created a dual boot of windows and openSUSE on their (legacy) systems.

The reason was quite simple, though hidden to users with little experience: the default for the bootloader during a fresh installation of openSUSE for a longer time had been to install the bootloader in the MBR, or to "Boot from Master Boot Record". This as well did lead to problems with the co-existence with other linux distributions in a multi boot.

One among other reminders of those problems is
which for legacy systems using an MBR is still valid.

Another reminder is
which was cited just recently
Quote Originally Posted by mrmazda View Post
Another option is to not put Grub on the MBR. Grub doesn't need to be on MBR to boot Linux. It can boot from the very same code Windows boots from, based upon which partition contains the boot flag. The flag can be moved among bootable partitions
I was astonished to remark that this default of "Boot from Master Boot Record", which in the past gave rise to so many problems on legacy multi boot systems, had returned.
I discovered that when I made a fresh install of Leap 15.0 some time ago.

Now for fresh installations of Leap 15.1 this default of "Boot from Master Boot Record" still was the same, and I therefore had to change that actively.

The solution was and is simple: in the checkboxes of YaST > Bootloader > Boot Code Options
- uncheck "Boot from Master Boot Record"
- check "Boot from (Root) Partition"
- check "Set active Flag in Partition Table for Boot Partition"
- check "Write generic Boot Code to MBR"

Then fdisk, parted, or other tools like gparted can be used to move the boot flag to the right windows partition to make windows updates work, and moved back again afterwards, without overwriting the MBR using a windows installation CD - which in turn would disable booting openSUSE.

Why making certain windows updates impossible, and in consequence force a number of less experienced users to destroy their linux bootloader setup, just by making this option of "Boot from Master Boot Record" the default of the openSUSE installer?