Problem with Internet Explorer settings

Hi, I don't know what I chose to 'block', but whatever it was it has now stopped Internet Explorer from working. When I open IE it comes up with 'Internet Explorer cannot display the web page'.
I have just used Google Chrome since, but software I need for uni uses IE!!
Please help!!

Microsoft blocks a lot of web sites when you are using a browser other than IE like Chrome or Firefox. Once you set your default browser to another company's product you're done. Contact Microsoft's tech support. I would put up a link to their support site for you but I use Firefox and they've got me blocked too.

The stupidity of it was that I changed to FireFox trying to get Microsoft's Automatic Updates to work. It's all about the money.