Вы можете использовать этот код:
Dim allDrives() As DriveInfo = DriveInfo.GetDrives()
Dim d As DriveInfo
For Each d In allDrives
'Console.WriteLine("Drive {0}", d.Name)
'Console.WriteLine(" Drive type: {0}", d.DriveType)
If d.DriveType = DriveType.CDRom Then
If d.IsReady = True Then
Console.WriteLine(" Volume Name: {0}", d.Name)
Console.WriteLine(" Volume label: {0}", d.VolumeLabel)
Console.WriteLine(" File system: {0}", d.DriveFormat)
Console.WriteLine( _
" Available space to current user:{0, 15} bytes", _
d.AvailableFreeSpace)
Console.WriteLine( _
" Total available space: {0, 15} bytes", _
d.TotalFreeSpace)
Console.WriteLine( _
" Total size of drive: {0, 15} bytes ", _
d.TotalSize)
End If
End If
Next