Things You'll Need
Instructions
Turn off the Playstation. Connect the Ethernet cable to the back of the PS3 and to your laptop.
Open Network Connections by clicking "Start," then "Control Panel," then "Network and Internet," then "Network and Sharing Center" and finally "Manage Network Connections," which is located on the sidebar on the left of the screen.
Right click "Wireless Network Connections," then click "Properties" and then click the "Sharing" tab. Check both of the checkboxes available here; it should say, "Allow other networks to connect through this." You should still have a wireless connection, but the Local Area Network (LAN) connection should be telling you there is a network cable unplugged.
Turn on the PS3 and go to "Settings," then "Network Settings" to test the connection. Now, the computer should pick up an "Unidentified Network" and the PS3 should tell you it was able to successfully connect to the Internet. You can use the Internet on your laptop and the PS3 simultaneously.