Frequently, after awakening my computer from sleep or hibernation I go to a browser only to get "this page cannot be displayed". It happens with Internet Explorer, Firefox, or any other browser (the error messages may be slightly different, but mean the same). If I reboot the computer, I have no trouble. After I've been using them for awhile, I often get the message "...not responding". Again, it seems the only way out is to reboot again. I don't know if these problems are related. I was told that one of the ports that is associated with my browsers may be closed.