IIS 7 - Basic Authentication - Default Domain - works only on certain machines

[jreed2132]

I'm trying to use Basic Authentication to log into IIS 7 from one domain to another.  I successfully log in if I provide a domain name with the username (ex:  domainname\username).

 

I'm trying to eliminate the user having to type in the domainname.  I found out using Basic Authentication, I can add a default domain name.  The problem is, it only works on some machines.  On the machines that do not work, they either default to the local machine name or the server name

 

Is there a setting somewhere on local machines that you specify a default domain?

 

If it helps any, we are using Windows XP/ Internet Explorer 7.