Member Avatar for number87

I have been having this problem with windows defender for a very long time. Whenever I click the update definitions on Windows Defender I get an error code and it is unable to update. My AVG antivirus and Comodo firewall have no problems updating. Even my windows update works properly. I tried disabling all firewalls but it is still the same problem.

If I cant solve this...how do I uninstall windows defender? I hate getting the pop up about outdated definitions file on startup...

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  • Latest Post Latest Post by Technocrate25

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Generated

Short, practical checklist for Vista Defender update problems (adds to , and others' suggestions)

If the manual update that linked fixed this case, great — but for later readers who still see update errors or codes like 0x800106ba (as reported by ), the usual causes are: the Defender service or its Windows‑Update dependencies aren’t running, definitions or engine files are corrupted, or the Windows Update agent/BITS/crypto stack is broken. Start with the quick checks below and work down the list.

  1. Check Defender service and its dependencies. Confirm the Windows Defender service (service name WinDefend) exists and that essential services (BITS, Windows Update, RPC/Cryptographic Services) are running — Defender won’t update if those are stopped. (learn.microsoft.com)

  2. Capture the exact error in the logs. Open Event Viewer and read the Microsoft‑Windows‑Windows Defender/Operational (or Security/Applications logs) for the event ID and message — that gives the best clue why an update or start failed. If the log shows file or signature problems, try the manual definition package from Microsoft (run as Administrator). (learn.microsoft.com)

  3. Repair local system/update components. Run System File Checker and inspect/update the Windows Update components if Defender won’t install definitions or the service won’t start. Example commands to run from an elevated Command Prompt (do these one at a time):

sc query WinDefend
sc query bits
sc query wuauserv

reg query "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware

sfc /scannow

Take care before editing the registry; back it up first. (learn.microsoft.com)

  1. If nothing helps: reset the Windows Update agent (stop BITS/wuauserv, rename SoftwareDistribution and Catroot2, re-register update DLLs) and retry the manual definition installer — Microsoft documents the reset steps. If a third‑party AV is installed, remove it cleanly first (they commonly disable Defender). If problems still persist, consider a system repair/restore. (bloggerblog0.blogspot.com)

Note: was right to warn against casually disabling the Defender service via Services — use the UI or follow documented procedures to avoid further side effects.

Recommended Answers

All 15 Replies

Member Avatar for Michael_Knight

Hi

Close Windows Defender from system tray, Right click the little icon next to the clock and select Exit.

If you delete the old update, checking for new updates will work.

To do this, Press Start > Run and type Msiexec /x {A5CC2A09-E9D3-49EC-923D-03874BBD4C2C} and click OK (you can copy and paste the Msiexec bit).

Open Windows Defender and check for updates.

If the above fails, try the following:

Windows XP and Windows Server 2003

1. Click Start, click Run, type wuaucpl.cpl, and then click OK.
2. Click Automatic (Recommended), and then click OK.

Windows Vista

1. Click the Start Orb, click All Programs, and then click Windows Update.
2. In the left pane, click Change settings.
3. Click to select Install updates automatically (recommended).
4. Under Recommended updates, select the Include recommended updates when downloading, installing, or notifying me about updates check box, and then click OK.

User Access Control - If you are prompted for an administrator password or for confirmation, type the password, or provide confirmation.

Member Avatar for number87

hmm....first few methods didnt work...
i tried install updates automatically but i got an error code too

oh yea...for the MSIEXEC bit i got an error saying this action is only available for products currently installed...

Member Avatar for number87

thanks! it works!

Member Avatar for Nick Smith

HI, just joined this site out of desparation. Suddenly Windows Defender is asking me for a password before I can access my e-mail account using Windows Mail (never did it before) but worse - when I complete it I am informed I have no new mail. But if I check mail2web.com, lo and behold I have mail waiting for me! Any clues as to what's going on? Defender will not allow me to update saying it does not recognise my processor (Intel Pentium dual core) I can't seem to disable Windows Defender as it tells me it's not running yet still keeps flashing up a password request.

Member Avatar for Adamsappleone

HI, just joined this site out of desparation. Suddenly Windows Defender is asking me for a password before I can access my e-mail account using Windows Mail (never did it before) but worse - when I complete it I am informed I have no new mail. But if I check mail2web.com, lo and behold I have mail waiting for me! Any clues as to what's going on? Defender will not allow me to update saying it does not recognise my processor (Intel Pentium dual core) I can't seem to disable Windows Defender as it tells me it's not running yet still keeps flashing up a password request.

You replied to an almost 2 year old thread.
Start your own thread for assistance.

Edited by Adamsappleone because: n/a
Member Avatar for Alanputotsky

My Windows Defender suddenly turned off and I cannot turn it on a message Error 0x800106ba appears pls help me to turn Windows Defender back on.

Member Avatar for Eumenio

Close Windows Defender from system tray, Right click the little icon next to the clock and select Exit.

Member Avatar for SGerrard

I have a similar problem whereby Windows Defender is now telling me that it doesn't recognize the Norton updates for malware? I know I should be able to use one or the other but I've been using a combination up until recently with no problems.

Member Avatar for Alanputotsky

There's no ICON beside the clock can't you understand that my Windows Defender turned off? pls don't give wrong advised ok?

Member Avatar for Alanputotsky

Tried you update procedure two times but the procedure just dissapears after I click open nothing happens

Member Avatar for caperjack

There's no ICON beside the clock can't you understand that my Windows Defender turned off? pls don't give wrong advised ok?

hi,posters you are replying to are only signature spammer and just typing shit ignore them .
i stoped using windows defender because of the broblem you are having ,i now use microsoft security essentials on all my computers as my virus and spyware ,with very good results.

had you read forum rules you would have see that you were to start your own thread and nopt tag a old one ,for best results

Edited by caperjack because: n/a
Member Avatar for Alanputotsky

I think you are right about Windows Defender

Member Avatar for Technocrate25

Note that a lot of guides have asked to disable Windows Defender service via Services in Control Panel and uncheck the startup item in System Configuration (MSConfig) in order to turn off Windows Defender and prevent it from starting up. This is uncessary, and it’s not a recommended way as any misstep will cause error message (explained below).
1. Run Windows Defender from Start Menu.
2. Click on Tools button.
3. Then click on Options link under “Tools and Settings” section.
4. Scroll down the “Options” page, and uncheck the check boxes of the following two settings:
Use real-time protection (recommended) under “Real-time protection options”

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