Windows Internet explorer 5.x

Can any body tell me which is the file which contains ip address and there host name and used while accessing internet using Internet Explorer ?

I have once accessed that file, to correct the problem of opening other site than what I was trying to open , as guided by 'Google.com'.

The problm was that , when I type 'www.google.com' in address bar of Internet Explorer(IE), the URL was atomaticaly changing to
'www.www.google.com.com' and opening totaly diffrent site. So when I opened that specific file on my computer as directed by 'google' I found that diffrent IP was assigned to 'Google' there. And so was the site opening instead of 'Google'. Same was happing with other sites like "Yahoo", "Rediff".

Now same problem has arrived again and I am unable to find that file. So can any body guide me ?

Pawankumar.