Internet not working correctly

Hello,

I have a problem with my internet connection, I have Window's Vista on my laptop and wireless internet. All my internet connection is working correctly and the connection is excellent,

However I can not connect to certain web pages. When i type the URL in sometimes the page loads and then says Internet Page cannot be displated. Other times the page just says straight away It cannot be displayed. I can get on some web pages like this one, but when i try get onto pages such as Google, it doesn't work!

I don't have any idea on how to fix this problem and need internet access to web pages for work with college,

Please can you help and run through how I can fix this problem, as I really don't know what to do.

Thanks