Hi Sriram,
Afaik you have to install Lab manager 4.0.3 on a Windows Server operating system. It has to be Windows Server 2003 SP1 or higher. See the Lab Manager Installation and Upgrade Guide for more information.
Regards, Robert
Blog: https://rvdnieuwendijk.com/ | Twitter: @rvdnieuwendijk | Author of: https://www.packtpub.com/virtualization-and-cloud/learning-powercli-second-edition