save folder

So what I'm trying to do is replace the new game with the 100% savedata i got from sagao.z and put into the game. However it came up with a couple of errors (from my guess) saying that the save data was incompatible. I look up some forums and was basically told to trashbin the whole save folder...

So, I'm planning to change my os from Win 7 to win 8 because I got some issues when I start another program (gdi laptop) And I'm still confused where rejet put their save data folder on disc C: (I always install the game on disc D:, and I'm too lazy for re-play their game if I got the new os...