Recently, Microsoft released a KB update that has installation issues on Windows.
We noticed this on a Windows Server 2019 where it was impossible to install KB5034439 because it reported an error during installation: 0x80070643.

To solve the problem, we expanded the WinRE partition (the recovery one, to be precise, to 1.5 GB) and the installation worked immediately and without any issues.

If you need a practical, safe, and fast tool to expand the partition, you can use AOMEI Partition Assistant. We used this very easily.

You can find it here: https://www.goline.ch/solutions/aomei/ and download the trial version.

UPDATE! IF THE PREVIOUS PROCEDURE DOES NOT WORK FOLLOW ALL THESE STEPS (Run a CMD.EXE with elevated privileges)

#
#Expand recovery partion with AOMEI Partition Assistant
#

#Assign a letter (R) to Recovery Partition
diskpart
select disk 0
select partion 3
#usually 3 is the recovery partition, but you can do a list partion to be sure
assign letter=R

#
#Format recovery partition with defaults and then copy install.win from DVD to GOLINE folder)
#
mkdir c:GOLINE
mkdir c:mount
Copy install.wim from DVD (D:sources to C:GOLINE or whatever)
#

#Mount the Recovery Media to a mount point (c:mount)
dism /Mount-Wim /WimFile:C:GOLINEinstall.wim /index:1 /MountDir:C:mount

#Copy all recovery needed files to the blank partition
Robocopy C:mountWindowsSystem32Recovery R:RecoveryWindowsRE winre.wim /copyall /z

#Active and enable the recovery image on R:
reagentc /setreimage /path R:RecoveryWindowsRE /target C:Windows
reagentc /enable
reagentc /info

#Remove the R: letter from Recovery Partition
diskpart
select disk 0
select partion 3
remove letter=R

#Dismount recovery media
dism /Unmount-Wim /MountDir:C:mount /Commit
rmdir c:mount

Perform a Windows Update and this time it will be successufully

### Expand recovery partition using Windows DISKPART tool ###

1. Run CMD.exe as ADMINISTRATOR
   
2. Run reagentc /info
   If you have the same case in this picture below, the partition is active and just only needs to be expanded
   
   

1. Run reagentc /disable
   
   
2. Run DISKPART
   
   
3. Too see the list of disks, run:
   list disk
   
   
   
   
4. Select the operating system disk with the commands
   sel disk #
   
   
   
   
5. To see the list of partitions of the selected disk run:
   list part
   
   
   
   
6. Select the operating system partition (usually it is the primary, verify the size of disk C:)
   sel part #
   
   
7. Run the following command to remove space from the selected disk/partition (The command removes 2GB from the selected disk/partition)
   shrink desired=2000
   The value is in MB
   A similar situation will be obtained (an unallocated space about 2GB)
   
   
   
8. Select the recovery partition
   list part
   sel part #
   
   
   
   
9. Delete the recovery partition
   delete partition override
   
   
   
   
   
10. Check if the disk where the partition needs to be created, is formatted in GPT or MBR
    Open Disk Management
    Right click on disk as showed
    
    
    
    On Volume tab, check Style partition:
    
    
    
    Based on the result obtained above run:
    
    GPT
    create partition primary id=de94bba4-06d1-4d40-a16a-bfd50179d6ac
    and then
    gpt attributes =0x8000000000000001
    
    MBR
    create partition primary id=27
    
    
    
    
11. Format the newly created partition
    format quick fs=ntfs
    
    
    
    
12. exit DISKPART
    exit
    
    
13. Re-enable reagentc
    reagent /enable
    
    
14. See reagent information
    reagentc /info

UPDATE! IF ALL PREVIOUS PROCEDURES DOES NOT WORK FOLLOW ALL THESE STEPS

First of all, mount the Windows Server ISO and restart the computer.
Select "Repair your computer," then "Troubleshoot," and then "Command Prompt."

Execute the following commands:

1- bootsect /nt60 sys
2- bootrec /fixboot
3- bootrec /fixmbr

diskpart
select disk 0 (the disk with the Windows installation)
list vol
select vol 1 (the volume typically with the C: drive)
assign letter=P
select vol 2 (the volume partitioned in FAT32)
assign letter=Q
exit

Q:
CD EFIMicrosoftBoot
attrib bcd -h -r -s
ren BCD BCD.old
P:
bootrec /rebuildbcd (Select A (All))
bcdboot P:Windows /s Q: /f uefi

EXIT and restart the server…
When the server has restarted, enter the command prompt with administrator privileges and run reagentc /enable

Voilà!
To verify: reagentc /info