Windows defender does not allow me access



I have been having a problem with updating my computer. Everytime I try to
install something an error comes up with Windows defender corrupt. I try to
access windows defender in the security center and it says application not
found. When I go to explorer C: and try to delete it, I get Error 0x80070091:
The directory is not empty. When I go and open the windows defender file
folder i get C:\program files\windows defender is not accessible. the file or
directory is corrupted and unreadable. So I cant open it or delete it or
reinstall it. I also cant go change any permissions to the program. Any
suggestions? Thanks

Bill Sanderson

This may be very bad

This is a pretty old article, however, and does not say that it applies to
XP or Vista, for example.

I'd open My Computer, right click the C drive, and choose Properties, then
the Tools tab.

Under Error checking, click check now, and check off both boxes, and hit

You will be told that the check cannot be done now because the drive is in
use, and asked whether you want to schedule it for the next startup. Say
yes, and then restart the machine, and allow the disk check to proceed.

When the check is completed, there will be a record of what was done in one
of the event logs, which you can cut and paste here if you want.

Let's see whether that takes care of the issue.

It does sound to me as though having a backup of your data would be a good
idea, though.


I did what you told me and it didnt ask me if I wanted to do it during next
start up. It started scanning then about 1/8th of the way it just stopped and
disappeared. I dont need to back anything up on this computer. I just need to
get this problem fixed. whatever the problem is preventing me from installing
updates. you obviously know a lot so what do you suggest.


Hello Shaun,

You might try this.

Go to the main Windows Update window and click on "Installed Updates" (on
the left-hand side of the window, at the bottom), and then remove "Update for
Microsoft Windows (KB931099)" (only).

Reboot. Reboot again. Go back to Windows Update, and re-install the same
update, by clicking on the Check for Updates button.

The above is assuming the OS is Windows Vista

Other folks may have additional ideas for you; hope this helps a bit, see if
that helps.

I hope this post is helpful.

Let us know how it works ºut.

Good luck


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