Dear Mike,

You have to configure a sub domain called forums in mydomain.com,
pointing it to your application folder.  Also, you need to change the url keys in the web.config file to indicate the new url.

As for creating the sub-domain, you need to create a DNS entry for it. 
If your domain name is hosted by a service provider's nameservers, you will need to request that they add the DNS entry for the sub-domain.

Oops.  Now the graphic line that seperates post from signature in all our posts is showing a broken link and is still pointing to the old domain, i.e.

   http://www.mydomain.com/instantforum34/images/line.gif

How can we get those to point to?

   http://forums.mydomain.com/images/line.gif

I changed all references in Web.Config.

Dear Mike,

Could you log into http://my.instantasp.co.uk and open a ticket?  When you do, please attach your web.config file to that ticket.

Dear Mike,

I'm glad to hear that it works!