I setup an application to install our new antivirus software automatically if it's not already on a machine when a user logs in. Is there a way to make a message come up before the install begins? We need to let them know that this is a mandatory update and that they should not cancel it.

I seen there's a pre-distribution scripting tab and a launch scripts tab, but what is the difference between the to? Also, I am not much of a scripter so which type of scripting language should I use for these?