To transfer photos from your Mac to your Windows PC, or from your Windows PC to your Mac, you can network the computers together via a workgroup and then enable file sharing on the computer from which you're sharing data. Both platforms enable you to share folders on an external drive, but to access your data on both systems, the drive must be formatted in the 32-bit version of the File Allocation System, or FAT32. New Technology File System isn't compatible with OS X, and Hierarchical File System Plus isn't compatible with Windows.

Share From Mac to PC

Step 1

Sign into your Windows PC and then press "Windows-Q" to open the Apps screen. Type "Command Prompt" into the search box and then select "Command Prompt" from the results.

Step 2

Type "net config workstation" (without quotation marks) into the console and then press "Enter" to see the name of your workgroup.

Step 3

Sign onto your Mac and then open "System Preferences" from the dock. Click "Network" and then choose your network connection from the left.

Step 4

Select "Advanced" from the bottom right and then enter the name of your workgroup into the Workgroup field on the WINS tab.

Step 5

Click "OK," "Apply" and then return to System Preferences. Click "Sharing" and then check "File Sharing."

Step 6

Click "Options" and then check "Share Files and Folders with SMB." Select your administrative account and then enter your password.

Step 7

Click "OK" then "Done." Choose "Read & Write" next to your administrative account and then click "+" under Shared Folders.

Step 8

Connect the external drive to your Mac and then select the folder containing the photos you want to share.

Step 9

Click "Add" to share the folder on your network and then write down the SMB address displayed under "File Sharing: On."

Step 10

Return to your Windows PC and then press "Windows-R" to open run. Type the SMB address and then click "OK."

Step 11

Enter the username and password for the administrative account on your Mac, and then click "OK" to access your shared folder.

Share From PC to Mac

Step 1

Sign into your Windows PC and then press "Windows-D" to switch to Desktop Mode.

Step 2

Right-click the signal bar in the bottom right and then choose "Open Network and Sharing Center" from the context menu.

Step 3

Choose "Change Advanced Sharing Settings" from the left, and then select "Turn on Network Discovery" and "Turn on File and Printer Sharing" under Private.

Step 4

Click "Save Changes" to enable file sharing on your network and then press "Windows-E" to launch File Explorer.

Step 5

Connect the external drive to your computer and then select the device from the left pane.

Step 6

Right-click the folder containing your photos and then choose "Properties" from the context menu.

Step 7

Click "Advanced Sharing" on the Sharing tab and then check "Share This Folder." Enter a name for the share, or use the default, and then click the "Permissions" button.

Step 8

Check "Full Control" to grant read and write permissions to the users on your network and then click "OK" to close each window.

Step 9

Press "Windows-Q" to open the Apps screen and then type "Command Prompt" into the search box.

Step 10

Select "Command Prompt" from the results. Type "net config workstation" (without quotation marks here and in subsequent commands) into the console and then press "Enter" to display the name of the computer and its workgroup.

Step 11

Sign onto your Mac and then open "System Preferences" from the dock. Select "Network" and then choose "Wi-Fi" or "Ethernet" from the left.

Step 12

Select "Advanced" from the bottom right and then enter the name of your workgroup into the Workgroup field on the WINS tab.

Step 13

Click "OK," "Apply" and then open "Finder" from the dock. Click "Go," then "Connect to Server," or press "Command-K."

Step 14

Type "smb://[server name]/[share name]" into the field provided. Replace "[server name]" with the name of the computer you're connecting to and "[share name]" with the name of the folder you're sharing.

Step 15

Click "Connect" and then enter the username and password for one of the accounts on your Windows PC.