I have a network at my office with wired and wireless networking that has been fine for 2 years. Just last week the wireless laptops have at times been unable to connect to the internet. The wireless icon has an exclamation poin which says no internet connecton. There is connectivity, but not to our server or to the internet. I have Webroot security on these computers and essentially all of the computers that have connection issues are windows 7 professional computers as the xp computers are affected much less. This occurred I believe just after a recent microsoft update. The computers may see the DNS server for an hour or two at a time then lose connectivity. This is occurring on at least 6 laptops at work. Strangely the computer may work again later without any change although at times i have turned to firewall off or Webroot off and if may or may not help connectivity. Even when I have no internet connection I can ping the server an config /all will see the server and the laptop has an address, but it will not connect to the server. The on or off connectivity seems very random and I have not been able to figure out the problem.