Client PC downloaded till 99% then it drops the patch

Question

Client PC downloaded till 99% then it drops the patch

Leon Toh 0

Hi all,

My company is using wsus server 2019 , and connect via intranet to my clients, we deployed win 11 for the client side, and recently we found out client pc download july patch up until 99% and dropped , and the other thing is it took a whole day to download the patch.

i had change wsus iis side to max kb transfer , added .psf MIME type to IIS , Ping Enable is set to Flase, Queue length is set to 25000 , and start mode is set to always running.

on client pc, registry editor i change disableduascan to 1 , NoAutoUpdate to 0 and WUServer and WUStatusServer are pointed to the wsus. and DODownloadMode = 100.

i tried stopped windows update , BITs , and CrpytSVC , deleted all file inside C:\Windows\SoftwareDistribution , and started back all three services , and stopped all HP services , Hotpatch tracking services. then run a gpupdate /force .

the download percentage on windows update gui did increase on a very slow crawl after that , but once it reaches 99% it drops the patches. even the small patches like security updates or windows edge updates are very slow.

Test-NetConnection returned true and on Get-NetAdapterStatistics | Select-Object Name, ReceivedBytes, i did saw the ReceivedBytes increase overtime.

I really dont know what to do next. Please help.

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2 answers

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Answer 1

Harry Phan 30,960 Independent Advisor

Hello Leon,

This looks less like a connectivity issue and more like a WSUS content validation or Delivery Optimization problem. If updates consistently reach 99% and then restart/fail, check the client's WindowsUpdateClient Operational log and Windows Update log for the exact error code.

As a quick test, set Delivery Optimization DownloadMode to 0 instead of 100 and retry on a clean client. Also verify that the affected July updates show 100% Downloaded in WSUS and that the corresponding content exists correctly in the WSUSContent folder.

The most important next step is to identify the exact Windows Update error code when the download drops from 99%. That code will tell us whether the issue is WSUS content corruption, Delivery Optimization, or Windows component store related.

Harry.

Leon Toh 0 Reputation points

2026-08-05T03:07:46.2433333+00:00

Hi Harry,

i checked the logs , i found a few error code on event viewer for July updates error code : 0x80244010 , 0x8024402C, 0x80072EE2, 0x8024002E and i saw 0x80240438 before the July update.

i tested on another pc using wifi dongle to connect to public wsus network, i manage to update july patch but when i connect back to my company's WSUS server for other packages like "Microsoft Edge-Stable Channel Version 149 Update for x64 based Editions (Build 149.0.4022.52)" ,"Microsoft Edge-WebView2 Runtime Version 149 Update for x64 based Editions (Build 149.0.4022.52)" ,and "Security Update for SQL Server 2025 RTM CU (KB5083245)" all restart/fail at 20%.

this is what it is showing on event viewer.

for quick test currently i dont have a extra new pc for it.

i dont know does this information helps or not , i stopped the windows update service, cryptsvc , and BITS. then i deleted all file inside C:\Windows\SoftwareDistribution , and started back all three services,the Delivery Optimization DownloadMode it was set to 1 before i change to 100.

Leon
Leon Toh 0 Reputation points

2026-08-25T01:14:41.67+00:00

Hi Harry ,

i had setup a client pc and change Dodownload mode to 0, from windows update logs i can see my pc is connected to wsus, and i tested by downloading the .cab files from the URL and it did download, but when i tried downloading the update patches it is being timed out by a power or network timer. how do i check if the network timer was set correctly ?

the windows update gui is still at 0% after i left it downloading for a whole day. what can i check next to try and download the patches ?

Hi AJ,

i had checked and set my wsus server and set MIME types according to your blogs and run the troubleshooting tests, while i did set the DOdownload mode to 0, on logic it should have downloaded at least 1-2% of the patches , but it didn't. is there other methods or advices you can think of that causes this issue ? or work around to allow the patach to download?

Again, i want to express my gratitude to the both of you for helping me out on this issue that i am encountering. So thank you for taking the time and sharing your experience to me.

Regards,

Leon
Adam J. Marshall 11,031 Reputation points MVP

2026-08-25T12:24:01.57+00:00

From the client that is having issues, share a gpresult /h gpo.htm with us

From the WSUS server, share the gpresult /h gpo-wsus.htm with us

I'm wondering if you have any policies that are affecting this.
Leon Toh 0 Reputation points

2026-08-26T02:49:08.21+00:00

Hi AJ ,

i would like to share gpresult for my client and wsus, but i can't due to company and client confidentiality.

are there any specific area on the gp i can check on instead ? i will share what i can but only in screenshots with redacted informations.

Regards,

Leon
Leon Toh 0 Reputation points

2026-08-26T07:03:52.73+00:00

Hi Aj,

i dont know does this help anything , but from windows update logs , it seems like there is some error

could this be the reason why it does not download at all ?

Regards,

Leon
Adam J. Marshall 11,031 Reputation points MVP

2026-08-26T15:47:39.2866667+00:00

Did you run the client side script on it? This seems like it's a client issue attempting to resume a download job with invalid or stale URLs cached vs the WSUS Metadata.
Leon Toh 0 Reputation points

2026-08-27T06:09:57.9033333+00:00

Hi AJ ,

Do you have a url for it ? i can't see the script that you post.

regards,

Leon
Adam J. Marshall 11,031 Reputation points MVP

2026-08-27T14:12:07.47+00:00

I don't know what went wrong there - it had 2 https:// in there on the forum - I fixed the URL - it should now work as it does for me.
Leon Toh 0 Reputation points

2026-08-28T07:30:55.32+00:00

hi AJ,

please ingore the previous comment ,I manage to open the link , and had ran those steps previously while browsing through your blog.

as for the client side pc , it managed to start downloading newer patches after I installed kb5094126 manually, while downloading i did a windows update log to see whats going on and found out wuauengcore.dll keeps on having this error.

eventhough the error presist , the download did continue ,and drop at 99% at the end with a error code as seen below.

any advice on this ? at the meant time i will continue on my testing also.

Regards,

Leon
Adam J. Marshall 11,031 Reputation points MVP

2026-08-30T13:35:45.2766667+00:00

Decline the update on WSUS

Run Server Cleanup Wizard

Approve the update on WSUS

Run the client side script on the affected client.

https://www.ajtek.ca/wsus/client-machines-not-reporting-to-wsus-properly/

Answer 2

Run a wsusutil reset on your WSUS server

https://www.ajtek.ca/wsus/what-does-a-wsusutil-reset-do-and-when-should-i-run-a-wsusutil-reset/

If it's a corrupt file, that will fix it. Once the reset is finished (wait 24h as there's no progress bar), see if the computers are now able to receive the updates.

You may also want to check to see if the detectoids issue plagues your WSUS server. If you had a licence to WAM, it would alert you if you had the test detectoids Microsoft issued a notice about.

https://www.ajtek.ca/blog/microsofts-wsus-service-degradation-how-wam-responded-in-record-time/

I recommend a Delivery Optimization Download Mode of LAN which numerically is 1.

If the WSUS Server itself is having trouble downloading the updates, you may need to force BITS foreground priority mode.

https://www.ajtek.ca/wsus/wsus-bits-foreground-priority-mode-vs-background-priority-mode/