A easy way to do this without modyfing file permissions so some bad people can take over the host file is too execute the following command line:
runas /user:administrator "notepad c:\windows\System32\Drivers\Etc\Hosts"
or
runas /user:administrator@domain.nl "notepad c:\windows\System32\Drivers\Etc\Hosts"
type your password and Notepad opens your hosts file wich you can edit as you like.
Have fun with this