You could try a VNC program, such as RealVNC - click here
Install it in both computers and then launch it in "Server" mode in your father's PC and "Viewer" mode in your PC. You need to set up a Password and then you connect to his PC by entering his IP address and the Password into your copy running in "Viewer" mode. You then have control of the remote PC, without your father losing control of it, i.e. you can either run it or monitor what he's doing with it.