update woes

I'm not sure if this is a networking issue or a software issue, but I'm having issues with updating windows and windows defender. Both give me the error message :
Error Found: Code 0x80072efd

I've tried manually updating, but that's giving me fits too. It's a windows vista system with Norton Internet Security. I've tried allowing all microsoft and windows processes in the firewall and still no go. Its also not allowing AdAware to update. I'm at a loss with this Vista thing. Any and all help would be appreciated including sending me in the right direction if I'm in the wrong forum. Thank you in advance!

Lori