If you try running ASP .NET development under Vista, you may find that getting to localhost does not work, although if you replace localhost with 127.0.0.1 it works fine.
I read a couple of posts talking about IPv6 and how if you disable it completely in the registry it fixes the problem. I didn’t fancy doing that! I then saw a post to just disable it in the network adapter that you’re using, but that didn’t work – I assume because localhost goes via the loopback adapter.
The easiest solution I found was to open the .hosts file in e.g. C:\Windows\system32\drivers\etc
and then add another : to the start of the last line of the file so that it looks like this:
This fixes the problem – I have no idea what it does though!