When on certain websites particually Amazon.co.uk, whenever i hit the back button it says page cannot be displayed. Then when i hit refresh it says there is a bug in the web browser i am using. I have to go back to the start every time and restart my search.

It says - Your Web Browser is Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; Sv1; .NET CLR 1.1.4322).

I thought i was using internet explorer as my web browser so what is Mozilla/4.0 and where have i got it from.

How do i eliminate this problem ?

I am almost certain this is a problem with their website and nothing to do with your pc. See this site