Trying to Edit the your host file in Vista usually does work.  By default, if you try to modify your hosts file in Vista, it will not let you save it. It tells you that you don't have permission or asks you to save as another file. Here's how to do it:

1. Start -> type in "notepad" in the search bar.
2. Right click "Notepad" and select "Run as administrator"
3. Click "Continue" on the UAC prompt
4. Click File -> Open
   
5. Browse to "C:\Windows\System32\Drivers\etc"
6. Change the file filter drop down box from "Text Documents (*.txt)" to "All Files (*.*)"
7. Select "hosts" and click "Open"
8. Make the needed changes and close Notepad.  Save when prompted.