Can no longer use 'back' button.


Recently I have not been able to use the 'back' button on Internet Explorer 8 when I am useing Hotmail. When I click on the back button I now get a whole list of ms ads.

What is this? Where did it come from? How do I get rid of it and how can I prevent it returning?

I am running Win XP Pro.

Any help or advice would be much appreciated.