exports series non stationary with correlogram but stationar

[enigma92]

Hello everyone! I am new to eviews and I just finished passed my econometrics course for the year(which does not include using softwares). Anyway I wanted to get a head start and understand using eviews.

I gathered time series data for my country from 1966 to 2012 and when I test using the correlogram and box - Ljung it suggests no stationarity after the second difference but unit root suggests its stationary after the 2nd difference.

Also both the correlogram show stationarity at the 4th difference but I read that differencing so many times makes the data lose valuable 'information'...

Any way I wanted some help concerning the issue