Were updates for Defender among those offered?
Windows Defender updates via Windows Update or AutoUpdate--so if either of
these is functional, the app should be able to be updated. However--clearly
there are some issues...
Is the definition version shown as 1.0.0??
(That shows at the bottom of the home page of the app.)
There used to be a KB article addressing this precise error--it's been
withdrawn : (
I'm not sure how to proceed at this point--usually, if no updates have been
received, it is because the user hasn't gone to WindowsUpdate, and
autoupdate isn't functioning for any number of valid reasons.
Most update issues I see involve machines where the updates have begun to be
received, but one particular update has failed to install fully. The fix is
to get that one removed, so that further attempts complete.
In your case, I can't tell from what I know so far whether any updates have
ever succeeded.
I think I'd proceed based on the idea that the very first update has failed
to complete.
http://support.microsoft.com/?kbid=915105
The first thing to try are the resolution steps from the above KB
article--don't worry about the premise--just use those steps.
Once they complete, please try updating via both of the possible
methods --in Windows Defender, Help, About, check for updates, or, Windows
Update.
If you get an error message in step1, the next thing to try is:
http://support.microsoft.com/?scid=kb;en-us;290301
The Windows Installer cleanup utility--download via a link in the above KB
article. Install it. Run it via Start, all programs. Scroll down the list
and find Windows Defender signatures--Remove this item. Then try updating
via both of the available methods.
I think one or more of the above steps has taken care of this issue for the
vast majority of folks who've had problems and posted here--who are, of
course, a very small minority of the actual users of the product--so I hope
you'll be able to give it a try, and that one of these methods fixes the
situation on your system.
--