来源：王国荣
此时可呼叫 GetModuleFileName API 函数判断执行档名称是否为 VB5，如果是 VB5
， 则GetModuleFileName 最右边的 7 个字元将等於 "VB5.EXE"，
Private Declare Function GetModuleFileName Lib "kernel32" Alias _
"GetModuleFileNameA" (ByVal hModule As Long, ByVal lpFileName As _
String, ByVal nSize As Long) As Long
Function IsRunUnderVB5() As Boolean
Dim S As String, Length
Length = 256
S = String(Length, 0)
Call GetModuleFileName(0, S, Length)
S = Left(S, InStr(S, Chr(0)) - 1)
IsRunUnderVB5 = UCase(Right(S, 7)) = "VB5.EXE"
End Function