My desktop Windows 7 computer is upstairs and it is connected by cable to my Linskys router also upstairs. The Windows 8 laptop is downstairs and receives the signal wirelessly from the home network from the router upstairs.

At the laptop the internet is working fine and I can see the files on my desktop upstairs, but upstairs I cannot see the files on the laptop downstairs.

Please can I be advised how to go about solving this problem.