This might help
Download Errors: “could not download virus and spyware definitions”
Restart Computer
Download and run CACLS Database Tool
Connectivity related errors, check Event logs for errors related to “content
headers” indicating proxy servers that do not support HTTP 1.1 through Proxy
Settings
Restart BITS and check if an error is encountered
If an error was encountered while restaring BITS follow steps in
troubleshooting BITS service
--
Prevention is better than Cure
"David F" wrote:
> I had installed the Microsoft Vista Performance and Compatible updates and
> it caused my Verizon Wireless 595 PC Card to not be able to work after
> waking up from sleep. I did a system restore to before the two updates.
> Both my Windows Defender definitions and my OneCare virus definitions files
> were out of date. Windows update took care of the Defender definitions, but
> the OneCare console does not allow me to update the virus definition file.
>
> Any ideas how to fix this?
> TIA
>
>