Hello, I don't use much windows 10 the last years, but I have them installed and I have this problem about a year now. I have windows 10 on first partition of an ssd disk(MBR, the system isn't UEFI), and I have 3 more partitions with linux distros. I tried to update windows sometimes until before a week but the last October's comulative update always failed to install with the message "failure to configure windows update reverting changes". Before some months I tried to fix it and I did all suggestions from microsoft's relative threads I found. Nothing worked. Before a week I gave it another shot and I did the only think I haven't try. This was to download the latest iso via media creation tool and update from that iso. This failed too and after a little googling I found a suggestion about making windows partition "active". Because I have dual boot in that disk and also have grub as bootloader was make sense that maybe this causes the problem(windows aren't very friently to other operating systems and filesystems). So, I opened windows disk managment and I tried to make windows partition "active" by right click on it and select this option from the context menu list. This had an unexpected result: Instead of making the windows partition "active", or give me an error message or a warning or someting, it just erased the 3hd linux partiton, which fortunately has a linux distro which I installed just for testing it. So, I'm asking if there is some way to fix this problem without to destroy the partitions of this disk or others I have? I don't care if I need to replace grub with windows bootloader(this I can fix later). I just don't want the disks and partitions to remain as is and functional. I don't have a separate system partition, windows boot files are on windows partition.
Your ssd has four partitions, and a MBR disk can only have a max of four partitions. Perhaps (i'm not sure at all) the windows installation process tries to create a recovery partition and fails.
An mbr disk can have a max of 4 primary partitons but if you make one of those partitions an extended partition and make logical partitions in it the number of drive letters is the limit of how many partitions you can make. I've been using this workaround for so long that I prefer MBR to GPT when either will work because I'm so familiar with it.
I have 2 primary and an extended partition with 2 logical. I don't care about the deleted partition, because it has a Linux distro which I installed it just to test it. I also have the /home partition in another disk, so all user data is there. I also use gparted in general but it hasn't an option for making a partition active. Has the "boot" flag though, which I' m not sure if is the same as active. EDIT: I just used diskpart as suggested above and the partition is already active(seems that "boot" flag in gparted is the same as active). So this means that this isn't the problem of failures. Maybe, as @rpo wrote above, the update search for a separate system partition and doesn't find one. Who knows if there is no a specific error message about the real problem.
Actually, on NTFS, you can use directories as Volume Mountpoints, so, drive letters is no longer a limiting factor.