this is a simple trick using windows task scheduler to notify VC when a user log in to PC or unlock it. in a similar way one can create a task when work station lock
it can be used to turn on the desk lamp, or make a funny comment, or trigger a timer that will remind the user to relax his/her eyes ...etc.
it uses the udp sender command line tools that is part of extras that one can download from the download page
open task scheduler then import the attached xml
it must be imported for every user if there is more than user on the PC and we want VC to interact with various users
for every user the run task under user must be adjusted ... and the path to where udp sender is placed