Windows 10: update KB5009543 fails

Update KB5009543 failed. Corrupted file?. It tries again and again, always failing. Most of the times starting the PC, it tries to install the update but fails. Takes a lot of time to start the PC, very irritating. Have tried to delete \softwaredistribution\download and the whole \softwaredistribution. No luck. Downloaded the update file from Microsoft Update Catalog. Still fails to update. In desperation disabled the Windows update service. No luck, it enables itself and tries again. Disabled the service sysmain. No luck. All other updates have installed fine. If this is not solved or if the

:)