We have to purchase the USB key for activation of Zview program downloaded from web site or get it from other researchers studying this field. Otherwise, we can't do analysis the data appropriately.
If I am right, Z view data files with all component data (real, imag, freq, theta etc.) in the form of text file can be imported into Ec-lab software (free software, along with Bio-logic) and can be fitted there with highly flexible interface. I have done it before.
Sorry, I need to disagree with Bihag Anothumakkol EC-Lab software it is not free software. For totally free software I recommend MEISP it is not easy to use, but totally free. Zview it is the best, but it cost 2000$ and NOVA has improved the software incorporating user friendly tools. If you work with potentiostats, ask your company to improved its software. Today almost all good Potentiostat companies (AUTOLAB, GAMRY, PALMERSENSE and IVIUM) provides good software for impedance analysis. Each program is different but all of them are quite good. It is only practise and practise...