actually it was my mistake in writing.It is not trial to full version,it is just that when we install a demo version on PC & after it gets over,& if we reinstall it again then also it gives a message that Ur trial period is over.Once i had done some KIDA with regestry entry & had been sucessful in making that trial version work again after uninstalling.But unfortunately,I had forgetten that trick.I just wanted to know that If u know how to do such a thing.