# Windows Defender/Update Error 0x800b0001: Unknown trust provider



## elemenohpea (Jul 6, 2013)

Hi Guys,

I'm getting the following pop-up from Windows Defender when I start the computer. The same message pops up when I try to start the service manually:

"Windows could not start the Windows Defender service on Local Computer.

Error 0x800b0001: Unknown trust provider."

I've also noticed the Windows Update is unable to search for new updates, giving an Error Code 800B0001.

I've done some searching around the web and nothing I've done seems to work. What exactly is this error and does anyone have any suggestions as to how to fix it?

Thanks.


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## spunk.funk (May 13, 2010)

Try the* Microsoft FixIt*: Windows Update Not Working.


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## elemenohpea (Jul 6, 2013)

Sadly (and ironically) the FixIt does not work. The installing gets about 60% ("Verifying the signature of MATSWizard_amd64.cab") before giving an error message: "We're sorry, but we couldn't verify the integrity of one or more components and cannot run the troubleshooter now. Please try again later."

Vague as always from MS...


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## spunk.funk (May 13, 2010)

Go to Start/Search and type* CMD *right click the* CMD* results and *Run As Administrator*. In the *Elevated Command Prompt* type *SFC /scannow *and press enter. This will replace any missing system files.


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## elemenohpea (Jul 6, 2013)

Hi spunk.funk,

I ran the command as you instructed and got this at the end: "Windows Resources Protection found corrupt files but was unable to fix some of them."

I have attached my log file below (saved CBS.log as CBS.txt) as it seems too big to copy and paste.


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## Corday (Mar 3, 2010)

Since iit found Missing Current State value for package connected to updates, try this>Start>services.msc>Find Windows Installer>Right click to start the service>Change the type to Automatic from Properties


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## elemenohpea (Jul 6, 2013)

Thanks Corday, I was able to do that successfully. Should I re-run "SFC /scannow" at this point?


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## Corday (Mar 3, 2010)

If updates work you should be fine.


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## elemenohpea (Jul 6, 2013)

Still the same error as before, even after a reboot.


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## Corday (Mar 3, 2010)

The CBS log appears OK. Go to this site and download the proper package for you unit:
System Update Readiness Tool fixes Windows Update errors in Windows 7, Windows Vista, Windows Server 2008 R2, and Windows Server 2008


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## elemenohpea (Jul 6, 2013)

Hi Corday,

I get the same FixIt error as before: The installing gets about 60% ("Verifying the signature of MATSWizard_amd64.cab") before giving an error message: "We're sorry, but we couldn't verify the integrity of one or more components and cannot run the troubleshooter now. Please try again later."

I am thankful for everyone that chipped in to help, but at this point, I think I'll be looking to do a clean install some time soon.


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## Corday (Mar 3, 2010)

If you have a retail version of Windows 7 you could try a Repair Install first. If it's an OEM version, you'd have to burn an ISO (we'll tell you how if you want) to try the Repair Install.


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## jenae (Jun 17, 2008)

Hi, this error is caused by the Cryptographic service, and if you go back to Spunk's post #2 and open the link, perform the manual fix (MS fix it's often don't work).

This has been known to fix this problem. To create a .bat file(batch file) copy paste the regsvr32 details into notepad, then select "File" and save as, call it defender.bat and save to desktop, locate the saved file and right click on it select "run as administrator", do the same for the much longer list of regsvr32's and save to desktop call it update.bat and right click select "run as administrator" to stop the services go to start, search and type:- services.msc (press enter) locate the relevant services and right click, select "properties" you can stop or start them here.


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