As long as a PC and a Mac are on the same wireless network, you can connect them wirelessly. To connect to a Windows 7 PC with a Mac, you first need to enable sharing on the PC. You can share individual folders or an entire hard drive. Before connecting to the PC from a Mac, you will need to know the name of the PC and you will have to enter a special command to allow the Mac access through Windows 7 security
Decide what information you want the accessible to the Mac computer. You can share a complete hard drive or limit access to one or more folders.
Click the "Start" button on the PC. Select "Libraries." Right-click the folder or drive you want to connect to the Mac. Click "Share With," and select "Advanced Sharing." A pop-up window will open.
Click the box beside "Share this Folder." It will say "Share this Drive" if you selected a drive in Step 2. Click "Apply."
Identify the name of the PC by clicking on the "Start" button. Click "Control Panel," then "System and Maintenance," then "System." Make a note of the computer's name in the "Computer Name" entry.
Turn on the Mac and launch the Finder by clicking on it from the Mac Dashboard.
Click the "Go" menu and select "Connect to Server."
Type "smb://ComputerName:139" in the text field, replacing "ComputerName" with the name of your PC. This syntax is necessary to get through Windows 7 Server Message Block (SMB) through port 139.
Wait for the Mac to make a connection to the PC. When it has succeeded, a dialogue box will open. Click "Guest." Click the "Connect" button. A second dialogue box opens, suggesting the name of a folder to mount on the Mac to access the PC.
Click the suggested folder. Click "OK" to close the dialogue box. The Mac is now connected to the PC. The PC drive or folder is now visible on the left menu of the Finder window.