without more info i can only assume certain things but when you reinstalled, did you save the old windows install/ drive? the game data is stored here "X:\Users\xxxxx\Documents\My Games\FINAL FANTASY XIV - A Realm Reborn". if that path is still there on the other drive, you just need to copy the folder over to where it needs to be on the new drive, and the game should be able to pick up the old saved data in theory.