'Link to MSDN documentation for this windows api

'#WTSQuerySessionInformation (Windows) http://msdn2.microsoft.com/en-us/library/aa383838.aspx

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, ByVal Source As Long, ByVal Length As Long)

Private Declare Sub WTSFreeMemory Lib "wtsapi32.dll" (ByVal pMemory As Long)

Private Declare Function WTSQuerySessionInformation Lib "wtsapi32.dll" Alias "WTSQuerySessionInformationW" _

    (ByVal hServer As Long, ByVal sessionId As Long, ByVal wtsInfoClass As Long, ByRef pBuffer As Long, ByRef dwSize As Long) As Long

Public Function GetClientName() As String

    Dim pBuffer As Long

    Dim dwSize As Long

    If WTSQuerySessionInformation(0, -1, 10, pBuffer, dwSize) Then

        Dim clientName As String

        clientName = String(dwSize, 0)

        CopyMemory ByVal StrPtr(clientName), ByVal pBuffer, dwSize

        WTSFreeMemory pBuffer

        GetClientName = clientName

    End If

End Function

Sub Main()

    MsgBox GetClientName()

End Sub