'Windowsログイン名取得API
Private Declare Function GetUserName Lib “ADVAPI32.dll" _
	Alias “GetUserNameA" _
	(ByVal lpBuffer As String, nSize As Long) As Long

Sub test()
	Dim strBuffer As String
	Dim lngLngs As Long
	Dim lngRet As Long
	Dim Get_User As String
	'
	' Bufferを確保
	strBuffer = String(256, Chr(0))
	lngLngs = Len(strBuffer)
	'
	' ログインユーザー名取得
	lngRet = GetUserName(strBuffer, lngLngs)
	Get_User = UCase(Left$(strBuffer, InStr(1, strBuffer, Chr(0)) – 1))
	'
	MsgBox Get_User
	'
End Sub