R – How to create a user account in Windows Vista using VBScript

If you're using .net 3.5 use this code instead.

To authenticate a user:

PrincipalContext adContext = new PrincipalContext(ContextType.Domain);

using (adContext)
{
     return adContext.ValidateCredentials(UserName, Password);
}

If you need to find the user to R/W attributes to the object do this:

PrincipalContext context = new PrincipalContext(ContextType.Domain);
UserPrincipal foundUser = 
    UserPrincipal.FindByIdentity(context, "jdoe");

This is using the System.DirectoryServices.AccountManagement namespace so you'll need to add it to your using statements.

If you need to convert a UserPrincipal object to a DirectoryEntry object to work with legacy code you can do this:

DirectoryEntry userDE = (DirectoryEntry)foundUser.GetUnderlyingObject();

OK, I found the script I was looking for:

QueryForUser("kenmyer")
Wscript.Echo "This user account does not exist."

Sub QueryForUser(strUserName)
    strComputer = "."
    Set objDomain = GetObject("WinNT://" & strComputer)
    objDomain.Filter = Array("user")
    For Each User In objDomain
        If lcase(User.Name) = lcase(strUserName) Then
            WScript.Echo User.Name & " already exists."
            WScript.Quit
        End If    
    Next
End Sub