Question : VIsta - unable to update Defender of get Windows updates

Hi - I'm running Vista and I'm unable to update Defender of get Windows updates - I'm also using AVG free which I'm able to update - I have a ADSL modem/router - other computers connect using XP are able to update.
any ideas? Tried turning the firewall off with no success

Answer : VIsta - unable to update Defender of get Windows updates

What happens when you try to get the updates:  any error message?  Have you looked at the Event Viewer to see if there is any information there?   (Start orb -> eventvwr.msc in the Run or Search dialog box and hit Enter key)  Also, what version of Vista?