Remove/Reinstall Win Defender on Win7 64bit due to procedure entry



I'm getting an error when I try to run Windows Defender: "The Procedure entry
point MpRegisterEventNotification could not be located in the dynamic link
library MpClient.dll"

I tried to reinstall Windows Defender from the Microsoft website but it says
it's an installed feature of Win7 and will not let me download it.

Is there a way to delete/reinstall Windows Defende on Win 7? or some other
solution to this problem?

Bill Sanderson

This is a new one for me.

The first question is whether you are running other anti-malware software
which may be intentionally disabling Windows Defender (and unintentionally
causing this error message?)

That would include AVG, in current versions, Microsoft Security Essentials,
and suites from McAfee or Symantec/Norton.

In Vista, the repair choice for this sort of error would be to run sfc
/scannow at an elevated command prompt (meaning right-click "command prompt"
in the start, accessories menu, and choose "run as administrator."--then type
sfc /scannow into that command prompt window and hit enter.)

That should do no harm in any case, if you wish to try it.
Feb 18, 2011
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I'm sorry to try to re-open an old thread but I cannot find anything else anywhere about this issue - I tried the sfc /scannow but it found "no integrity violations" - I'm not sure what it was doing anyway! I've tried disabling Windows Defender but it will not open and I get "MpRegisterEventNotifier could not be located by MpClient.dll" if I try.

Appreciate any help anyone can give.


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