Active directory on a local windows 7

See more:

ASP.NET

Windows

Win7

, +

Hello.
I am developing an ASP.NET website. One of its features is authenticating using active directory. At developing time, (right now) i have no access to network with a server computer. So i need to work on my windows 7 ultimate. I downloaded active directory stuffs from microsoft.
When i try to logon my website with ldap address, i get this error:

The specified domain either does not exist or could not be contacted.

To use LDAP address, i need to my windows joined to a domain, Right?
Ok, but my computer is not connected to any network or server computer. Can i define a domain for local computer? How is it?
Or maybe i am trying to login in wrong way. this is my code

bool authenticated = false;
try
{
    string server = "LDAP://real.domain.com";
    DirectoryEntry entry = new DirectoryEntry(server, Environment.UserDomainName + "\\" + user, password);
    /*  DirectoryEntry entry = new DirectoryEntry("LDAP://"+ Environment.UserDomainName ,user, password);
    */ //DirectoryEntry entry = new DirectoryEntry(server, user, password);
    object nativeObject = entry.NativeObject;
    authenticated = true;
}
catch (DirectoryServicesCOMException cex)
{
     //not authenticated; reason why is in cex
}
catch (Exception ex)
{
    //not authenticated due to some other exception [this is optional]
}
return authenticated;

The code throw exception at DirectoryEntry initializing.

Thank you!!!
A.H