You could use something like WinVNC (click here).
Install it on your machine before you go, start it up (WinVNC Server) and then leave it running while you go to Durham.
When you get to Durham, download the program onto your son in law's computer and run the viewer. Type in the IP address of your computer, enter the password you set and you should connect to your computer at home.
p.s., WinVNC is free