如果你想通过VB打开或者关闭CD-ROM，你可以向Windows Multimedia DLL发出一条相关的命令请求，但是你必须先声明DLL：
在模块文件中加入以下代码：
Declare Function mciSendString Lib "winmm.dll" Alias _"mciSendStringA" (ByVal lpstrCommand As String, ByVal _lpstrReturnString As String, ByVal uReturnLength As Long, _
ByVal hwndCallback As Long) As Long
以下是打开CD-ROM的过程代码：
retvalue = mcisendstring("set CDAudio door open", _
returnstring, 127, 0)
关闭CD-ROM用以下代码：
retvalue = mcisendstring("set CDAudio door closed", _returnstring, 127, 0)
……