The fact that your w7 machine cannot detect your network which is broadcast by your router is an issue you need to solve. It's not w7, rather possibly a router setting that your friend may have imposed. I do not know, if there if this is the case, and if you do not know yourself than you can do what i suggested. Reset your router and re-setup your network. I do not believe if a router is properly setup, w7 cannot detect it.
Note: passwords can be setup anytime after you reset the router. i'm not telling you to leave the password as default.