the trial works a month from installation date... sets it´s date in the register in Windows.... just sayin... thats the only protection as far as I can see.
here is the latest if someone is interested
http://www.hikvisioneurope.com/portal/index.php?dir=Software/01%20%20%20Video%20Management%20Software/03%20%20%20iVMS5200/v3.02.202/