Hi, We have a program, made with C#: that's why I am here :-). In order to check for a drive existence, we use System.IO.Directory.Exists, giving the drive letter and root folder as parameters (i. e., "C:\\"). Under Windows XP it runs just fine, but under Windows Vista, the call always return false, even against C:\. Could anybody give us any advice about it...? It's driving us nuts!! :confused: Fidel Leon - EA3LF