You need a Crossover cable.
This will allow the two computer to communicate as if there were a switch or router between them, and allow you to bridge to the wireless connection.
Also make sure all the required services are set to automatic and are running.
Click Start, Run, type services.msc, and click OK. To enable a service, find it in the right pane and double-click its entry. Be sure its Startup Type is set to Automatic and click OK. All the following services must be configured in order to use ICS:
- Application Layer Gateway Service
- Network Connections
- Network Location Awareness (NLA)
- Plug And Play
- Remote Access Auto Connection Manager
- Remote Access Connection Manager
- Remote Procedure Call (RPC)
After verifying and/or configuring Automatic startup for each of these services, close the Services window and restart the computer before attempting again to enable ICS.