Здравствуйте, labslo, Вы писали:
Имеем:

BOOLEAN GetUserNameEx(
EXTENDED_NAME_FORMAT NameFormat,
LPTSTR lpNameBuffer,
PULONG nSize
);
и
typedef enum
{
NameUnknown = 0,
NameFullyQualifiedDN = 1,
NameSamCompatible = 2,
NameDisplay = 3,
NameUniqueId = 6,
NameCanonical = 7,
NameUserPrincipal = 8,
NameCanonicalEx = 9,
NameServicePrincipal = 10,
NameDnsDomain = 12
} EXTENDED_NAME_FORMAT, *PEXTENDED_NAME_FORMAT;

Немножко думаем и получаем:

Private Enum EXTENDED_NAME_FORMAT
  NameUnknown = 0
  NameFullyQualifiedDN = 1
  NameSamCompatible = 2
  NameDisplay = 3
  NameUniqueId = 6
  NameCanonical = 7
  NameUserPrincipal = 8
  NameCanonicalEx = 9
  NameServicePrincipal = 10
  NameDnsDomain = 12
End Enum

Private Declare Function GetUserNameEx Lib "Secur32.Dll" Alias "GetUserNameExA" (ByVal NameFormat As EXTENDED_NAME_FORMAT, ByVal lpNameBuffer As String, ByRef nSize As Long) As Long

Private Sub Form_Load()
Dim sName As String * 255
Dim lenght As Long
lenght = 255

GetUserNameEx NameFullyQualifiedDN, sName, lenght
MsgBox sName
End Sub

Но помним что:

Client: Included in Windows XP and Windows 2000 Professional.
Server: Included in Windows Server 2003 and Windows 2000 Server.
Unicode: Implemented as Unicode and ANSI versions.

Всего-то делов