FPSC V-Packer does NOT work with Windows Vista (at least)
Problem 1: The game.exe hangs for 10-20 seconds. ie if you quit the game and try to restart it won't start. Look in Task Manager/Processes and you'll see it's still running for ages after.
Problem 2: If you close it from Processes the game will never run again no matter what you do. Even a system restore will not bring the game back.
THIS IS NOT THE CASE WITH THE TRIAL VERSION!!!!
My advice is, when you get the above problem, demand a refund. When they tell you they don't give refunds because you got the trial first make sure you tell them the problem does not exist in the trial.
I expect to get banned again for pointing out that this prblem exists so please repost it when I'm gone.
Vishnu packer is better even though you get the "Works with X9 only" giveaway in the xbox controller option. (Just call your game Zombies X9