# Error code 0xc00021a, installation of file causing problem



## EricHes (Nov 4, 2014)

Hello,

I recently got a new laptop, which worked perfectly fine until a while ago. A few minutes after startup, the error message 0xc000021a would pop up, making the pc reboot. I tried finding a solution for this on the internet, and found a one on Windowsinstructed's site, which suggested to start the pc in safe mode, and execute the following two commands: 

- DISM /image:C\ /cleanup-image /revertpendingactions
- move C:\Windows\WinSxS\pending.xml C:\Windows\WinSxS\pending.old

I proceeded to do these steps and restarted my pc, however, this did not resolve the problem afterwards, so I refreshed windows 8 using advanced options. This fixed the problem, but after I installed everything I needed again (and removed everything I didn't need, like some Acer applications and some bloatware), this error popped up again. 

Is there any way I can easily see what is causing the problem without needing to tediously check programme after programme what is causing the error? I can just refresh the OS again and not install any of those programmes, but most of them are essential for me.

The things I installed after refreshing were:

-Start8
-Google Chrome
-Comodo Antivirus
-Microsoft Office
-Modernmix
-utorrent
-Steam
-Winrar

Thanks in advance!


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## joeten (Dec 4, 2008)

Hi and welcome to TSF we could use some info on what you removed and what you used to remove it, since you did this before and it is now repeating the issue, it indicates you may have removed something which had a shared use.


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## EricHes (Nov 4, 2014)

joeten said:


> Hi and welcome to TSF we could use some info on what you removed and what you used to remove it, since you did this before and it is now repeating the issue, it indicates you may have removed something which had a shared use.


Thanks, I simply used the control panel to uninstall programmes, no software of any kind. I removed:

-AcerCloud Docs
-Acer Recovery Management
-Acer Identity Card
-Acer Live Update
-Acer accessory Store
-Acer Initiatives (I think)
-Acer Explorer
-AcerCloud Portal
-McAfee
-Amazon Weblink
-Spotify
-Ebay
-A handful of pre-installed windows 8 app games

As you can see, my laptop had a lot of bloatware. >.>


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## joeten (Dec 4, 2008)

Hi something has corrupted win logon services, we need an analyst for some suggestions on the best approach as there are a few things which might be tried, however, I would prefer to let them advise as to which has a better chance of success. This can be a tricky one to fix properly.


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## Jared (Jul 20, 2013)

Can you upload the dump files for analysis.

Go to


```
C:\Windows\minidump
```
Upload all those files by *copying* (Make sure you copy the files otherwise you will get access denied, even if you're an administrator) them to the desktop and compressing them in a single .zip folder.

Or even better, upload a Kernel memory dump.

Go the Start
Right click My Computer
Select Properties
Click Advanced system settings
Click on the Advanced tab
Select Settings under Startup and Recovery
Then under Write debugging information select Kernel memory dump.

Once a dump is created go to:


```
C:\Windows\memory.dmp
```
*Copy* the file to the desktop, zip it up and upload it to a file sharing site like Onedrive. After the upload is done post the download link in your next reply.


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## EricHes (Nov 4, 2014)

Nevermind, I fixed the problem. After refreshing again, I found the guilty culprit. It was an addon I installed for Microsoft Office, which apparently was not compatible with windows 8. 

Thanks for the help anyway everyone.


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## joeten (Dec 4, 2008)

Glad you found it, Could you post what add on it was, it may help others avoid a similar problem.


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