to see just open the start
in the search programs and files write CMD
it will open a dos command window
inside there write "net view" then enter
if you are reviving an error like "error no. 6118" that's because you have the fire wall blocking the ports
you just need to disable the fire wall for few moments to see trough the router
to disable the router go to control panel and in the search at the top right write fire wall
inside there just disable it and rewrite the command inside the cmd "net view"
you will see who is using your internet
* you cant see if you are not the admin or if its not your house net
to activate the fire wall you just click on the alert and it will be turned on automatically
If it was useful please g+1