Well, I still don’t see this file as being the problem, although it is odd that it is empty. XP Pro ships with the file’s contents as I put in my post. I’d guess whatever bug you’ve got cleared the file so you couldn’t shortstop it. Or one of the tools you’ve already tried cleared the file as a precaution.
It doesn’t NEED to have anything in it. It exists only to provide shortcuts to url’s so your PC doesn’t need to lookup the IP address for a url on a DNS server somewhere. Putting “wrong” entries in it is useful to prevent popups and other content on webpages from finding the correct address on a DNS — a bad address means that popup or whatever fails to run, which is exactly what you want sometimes.
I finally got TDSS Killer to work. It was the “Volsnap” virus. It’s apparently new and hard to find/get rid of.
Thanks for your advice.