Today, i accidentally disconnected my controller, and then the game won't detect it after I reconnect. After a bit of searching on google, other players found that rebooting the pc might help. So, i decided to reboot pc. Just right after i reboot my pc, game deleted itself again. this is the 3rd fking time now. FKING AID

This problem is common if you did not install to the C drive. Apparently Windows doesn't like it when PSO is located on a drive different than the Windows installation.