Norton live update says no connection found when I am online

Just installed norton because i was have problems with other virus program not updating still having same problem pretty sure i have a virus because 2 porn sites i never been to before on my desk top and i read other people having the same problem in conjuction with this my windows fall to update also i’m running windows vista 32 bit sp 1 with nis 09 also ontop of the other problems sometimes the computer goes crazy reboot internet explorer locks up stuff like that any help would be thankful.