Renaming "hosts" file

how to remove extension

[vivalasvegas]

Trying to add a line to my hosts file to stop Adsense ads from showing I renamed the file to hosts.txt. Now I can not revert it back to its original file type (whatever that is). I understand that this file should have no extension. Is there a way to remove the TXT extension?

Thanks

[kevinpate]

Save the file as "hosts" instead of hosts.txt
[include the " " around the word hosts]

[vivalasvegas]

Thanks Kevin.