Auto Run Program on Web Page Load

I need to be able to automatically run and install a program whenever a web page loads. It should be able to do so without any prompt or notification to the end user (prior acceptance has already been given). Also, it should not be flagged by adware, virus or firewall software, nor by the end user's browser. I realize that to accomplish this 100% may be pretty much impossible, but I need the best possible solution available.