Windows Defender Won't Install After Malware



Following a malware attack ("Security Antivirus") that was removed using
Malwarebytes, the Windows Defender service would not start on my XP Pro SP2

I uninstalled the program, and downloaded the current version from
Microsoft. During install, I get to the "Starting Services" step and the
following error occurs:
"Service 'Windows Defender' (WinDefend) failed to start. Verify you have
sufficient privileges to start system services." Before clicking either the
Retry or Cancel buttons, I modified the permissions of the registry entry
"HKLM\Software\Microsoft\Windows Defender" from "Read" to "Full Control". for
Administrators, Users & Everyone. Then I clicked on Retry, but the same
error repeats. I've reviewed all the other similar posts, but can't figure
this out. I would appreciate any other ideas.


Any others Security programs running in the background, Microsoft Security
Essentials, Microsoft Forefront Client Protection, or, perhaps, Microsoft
Live OneCare. GetRight Zone Alarm Firewall, Spybot Search & Destrot (Having
uninstalled Spybot without first fully disabling Spybot Tea Timer) could be
the cause of this behavior

Try to remove it with Revo Uninstaller, then run CCleaner's registry cleaner.


But use the REVO uninstaller (fourth/last option). That way you are
certain to scrap all the registry entries - and malware packs have a lot.

Also, try in Tools -> Optimization -. Junk Files Cleaner – Scan -(give it
some time)- Delete

Also, Tools -> Tracks Cleaner, for
Browser Cleaner
Microsoft Office Cleaner
Windows Cleaner
Evidence Remover
Unrecoverable Remover

Note, uncheck Yahoos Toolbar

Download the basic version via
The basic version does not contain the disgusted Toolbar



I have McAfee VirusScan, but that was running before with Defender. I'm not
sure what you meant by "Try to remove it with Revo Uninstaller" because as I
said in the original post, I removed the malware using Malwarebytes. I did
run both the Revo Junk Files Cleaner and CCleaner's registry cleaner, but
still get same error.

Bill Sanderson

Is this the same version of McAfee which was running before the malware

If not, check with McAfee support to see whether the current version
intentionally disables Windows Defender--this is quite likely.


XP? then.

Unistall Mcafee, using How to uninstall or reinstall supported McAfee
consumer products using the McAfee Consumer Products Removal tool (MCPR.exe)



Again, CCleaner and/or Revo.


Install now Windows Defender.


Now, reinstall McAfee.


Good luck

Extended Support for WinXP SP2 ends on 10 July 2010. After that date,

computers running WinXP SP2 will NOT be offered any further critical

security updates, Automatic Updates will not work, and Windows Update

website will not be accessible until SP3 is installed.

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