Option Explicit Private Declare Function GetCurrentProcess Lib "kernel32" () As Long Private Declare Function IsWow64Process Lib "kernel32" (ByVal hProcess As Long, ByRef Wow64Process As Long) As Long   Private Sub Command1_Click()     Dim lngReturn As Long     Call IsWow64Process(GetCurrentProcess, lngReturn)     If lngReturn = 0 Then         MsgBox "非64位OS"     Else         MsgBox "64位OS"     End If End Sub