hmmm... WHY ?

Why would you want your systems that can run a logon script in the first place to be UNMANAGED ? You can probably get a cheaper AV solution if you're not going to manage them.

Managing the clients will make life easier and cheaper for you in the long run though.

But... you can look at my UDF to see how I'm checking the DEFINITION date and then create your own code, or use my UDF and take action based upon results.