Why would you be using VB6 to do this ? It's out of date and obsolete. It was always hideous.
If you were to use a real programming language, like C# or VB.NET, then you could use this code:
http://www.dreamincode.net/forums/showtopic135795.htm[
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But even detecting the event doesn't necessarily mean you can stop it running. Your friends should not trade porn and warez using their flash drives, then they would not have an issue. Stopping auto run from working is also a good option, you could configure that for them.