Loadrunner Truclient Required- Truclient Browser

When I try to replay the script with different system proxy using Truclient Browser it always asks for authentication from TruClient Browser and my script fails. My script doesn't start and this authentication comes up before that. So when I try to replay the script it fails because of this. I cant keep it as a step to do : authenicate dialog because these pop up comes right before I can replay my script.