Internet Explorer cannot display the webpage + since upgrading to NIS 2011

Hello, I upgraded from NIS 2010 to NIS 2011. I have Vista 32 bit. Since installing 2011 I cannot get to many pages on the internet. I often get "Internet Explorer cannot display the webpage". It happens 75% of the time. I have tried disabling parts of NIS to see if it makes a difference but it did not. Also, sometimes instead of getting the webpage, I get the webpage in text...with a tree of content. I am hoping someone can advise me. I also tried using Mozilla Firefox and Google Chrome with the same outcome. Thank You.