Fixing Windows Update error 0xC800021F

Posted on 2005-12-17 by Marc

I was trying to run Windows Update and Microsoft Update to get all the updates for a Windows 2000 installation that I’m running in a QEMU virtual machine on my Ubuntu Linux box, but it kept failing with error 0xC800021F.

Luckily, I found this page which recommended the following sequence of steps which seemed to fix the problem:

regsvr32 MSXML3.dll /s
net stop wuauserv
cd /d %windir%\SoftwareDistribution
rd /s /q DataStore
net start wuauserv

Now that it’s working, I have 27 security updates to download!

20 thoughts on “Fixing Windows Update error 0xC800021F”

rttech on 2005-12-30 at 4:41 pm said:

Worked perfectly! Thanks!
Wren on 2006-02-17 at 8:16 am said:

Excellent advice – worked like a charm! Thanks so much!
Bruno Turcotte on 2006-03-01 at 2:51 pm said:

Thanks! It solved my problem too.
faked on 2006-03-02 at 7:22 am said:

It solved my problem too! I’m running a Dutch version of Windows 2000 Professional SP4.

Thanks to Marc Abramowitz and to Google for indexing this page 😉
Marc on 2006-03-02 at 3:27 pm said:

Wow. How annoying that Windows Update/Microsoft Update is so buggy. A lot of people must be running into this “0xC800021F” bug it seems, based on the number of comments coming in (this seems to be one of the most popular posts on my site!). Anyway, I’m glad that this fix fixes the bug for so many people.
Eddy on 2006-04-25 at 8:10 pm said:

Excellent! It works now!
tech-er on 2006-08-30 at 2:50 pm said:

Thanks so much. This worked perfectly!
I am running W2K SP4. Today is Aug 30, 2006.
This got the Windows Update and Microsoft Update working.
Ketunraato on 2006-09-06 at 1:31 am said:

And still thanks, even if its already end of summer. Got my stepsons comp updated, thanks to You.
Matt on 2006-09-17 at 5:05 pm said:

Wow! I’ve looked all over for this…It worked great! Thanks.
Marc on 2006-10-27 at 5:05 am said:

test
Marc on 2006-10-27 at 5:07 am said:

0xC800021F
Marc on 2006-10-27 at 10:32 am said:

0xC800021F 0xC800021F
stone on 2006-11-29 at 11:28 pm said:

it worked great! thanx for posting that 🙂
Jason on 2006-12-22 at 2:04 pm said:

Thanks a ton!
Kerry on 2007-01-11 at 1:07 pm said:

Worked great…Thanks for posting this. As of Jan 2007, this error is still not part of the MSKB!! Go Figure!

k.
luke on 2007-03-07 at 9:53 am said:

thanks a lot!!!
Mike on 2007-03-28 at 12:42 pm said:

Couldn’t ask for anything easier or better. Thanks alot
Cheers!!!
poomsky on 2007-04-21 at 3:39 pm said:

Wow, Thanks.
MC on 2007-05-09 at 1:33 am said:

Thanks – (manual) Win2k SP4 updates now working.
Paul on 2007-05-29 at 10:24 am said:

Thanks, worked fine

20 thoughts on “Fixing Windows Update error 0xC800021F”

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