KB5034441 fails to install with error code 0x80070643.

SusanBradleyGeek  I had the same issue.  I hope the solution I stumbled upon helps others.

When updating windows KB5034441 I would get error 800070643 with no installation.

Thing I have tried, the did not solve the issue.
- increased recovery partition to 1.93MB (in stages)
- windows troubleshooter - updates
- restart computer
- SFC /scannow
- DISM.EXE /Online /Cleanup-Image /RestoreHealth
Nothing worked!

SOLUTION
note: Recovery partition must be immediatly after C: partition
Make recovery partition 1GB by:
use DISK MANAGEMENT to shrink C:
Use GPARTED boot to expand Recovery partition into space created by shrinking C:
note: Disk Managment is must faster at shrinking that GPARTED
Open CMD in administrator mode
reagentc / disable
reagentc / enable
Try the update again. HAZZA! Update installed.

I hope this helps someone in the future.