If I put a url in the address window which is not in my favorites
Are you entering
www.xxxxxxxxxx.com? Does the URL in the address window automatically change to
http://www.xxxxxxxxxx.com?
What happens if you enter
http://www.xxxxxxxxxx.com in the address window?
Are you sure you are not looking at an offline copy of the favorite site?
Check that you can resolve the URL to an IP address:
Run, CMD, ping
www.xxxxxxxx.com (I usually use
www.bbc.co.uk or
www.dell.com, as these both respond to ping requests).
Check that A) it resolves the web address to an IP address and B) that you get a response.
If A is fine then DNS is OK, if both are OK then it's definitely a browser problem, rather than a network problem.