How to convert Lead into Account in zoho crm?

How to convert Lead into Account in zoho crm?

Hi, I have two Zoho CRM instances and I am facing a strange problem.
From one instance, when I convert Lead, It is converted into Account, Contact and Potential (Optional).
But from other Instance, when I convert Lead, it is only converted into Contact and Potential (Optional), is not converting into Account as well.
I want to convert Lead into Account, Contact and Potential.
What is the problem? 
I am not using any deluge script or any thing else.

Please help.
Thanks