Hi Arpit Verma,
May be evaluation version of optisystem was used in your system earlier. Since a version can be used only for once in a system, it won’t work again in your system ( if you have used the evaluation version earlier for 30 days). If its not so, I am sorry. Attaching the snapshot of the error message will be helpful for you as well as the members of this forum to help you.
Regards.