Member Avatar for azriel

Just got this comp about 2 months ago and having issues where Windows Defender refuses to boot up and I can't receive automatic or manually induced windows updates. When I try to kick off a manual update it tells me error code 80096001. If I try to start Defender it says application failed to initialize: 0x800106ba.

Can can I delete it and re-download it? Any suggestions?

Thx in advance.

-Az.

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Short, practical guidance for and others seeing Windows Defender fail to start and Windows Update fail on Vista. As noted, Defender behaved differently on XP (standalone download) versus Vista (built in), so troubleshooting steps differ. Also note that Windows Vista reached end of support in April 2017; some update/signature distribution behavior may no longer be current on that platform.

Quick checklist (in roughly the order to try):

  • Confirm no third-party antivirus is installed and actively disabling built-in protection; many AV suites disable Defender automatically.
  • Verify services are present and running: Windows Update, Background Intelligent Transfer Service (BITS), Cryptographic Services, and the Windows Defender service.
  • Repair system files with the System File Checker (sfc /scannow) from an elevated command prompt.
  • Inspect the Event Viewer (Application and System logs) for specific error entries from Windows Update or Defender and note exact event IDs/messages.
  • Reset the Windows Update cache and catroot2 (this forces Windows to recreate its update catalog state).

A common reset sequence (run an elevated command prompt):

net stop wuauserv
net stop bits
net stop cryptsvc
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 catroot2.old
net start cryptsvc
net start bits
net start wuauserv

Notes and cautions: renaming SoftwareDistribution/catroot2 clears the update cache/history (installed updates remain). Creating a System Restore point or a backup before making changes is recommended. If Defender files are damaged and SFC cannot repair them, options include an in-place repair using Vista installation media or a clean install — upgrading to a supported OS is strongly recommended for security. Exact Event Viewer messages or service error codes will guide further, particularly if any of the stop/start commands return errors.

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Member Avatar for mmmmmmmmmmmm

yh i got that message with defender in xp

you are using vista i assume?

Member Avatar for azriel

never had this prob w/xp - YES am having the issue in vista

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