Here is a copy of the host file that I use. (Right click Save As) and then save it over your old host file (making sure it has no extension). The old host file can be found at:
Windows XP = c:\windows\system32\drivers\etc
Windows 2K = c:\winnt\system32\drivers\etc
Win 98/ME = c:\windows
This file contains a list of web sites you’d rather your computer not bother to look up. For example a site that uses advertising from the DoubleClick advertising network would show it’s own content but not the ads if you had the line 127.0.0.1 ad.doubleclick.net in your hosts file.
The host file can also prevent tracking which sites you use. I can’t tell you what a big difference a good hosts file can make in your browsing experience. Find out more about host files.