Just open e-shayata at icai.org and lodge your query there. They will give u the login Id and password. No need of fresh registration for every attempt. you are required to fill exam form only.
Before filling exam form, need of fresh registration as a new user( as shown in icaiexam.icai.org) is required for every attempt for Cpt, ipcc & final. This is only for exam purpose n to get new username & password.
CAclubindia
