Both must be in the Same Workgroup and if any firewalls are runing, they must be configured to allow local traffic.

The "ethernet" cable must be a crossover cable for direct connections, not a regular cable.

There are two ways of doing it :

1. connect both the computers with the Ethernet cable without the Swtich and allow the File and Print sharing, and client for microsoft network.

2. Connect using the switch and just allow the firewall settings to pass through