How to Copy a File or Folder to a USB Drive on a Mac

What you need: A Mac and a USB flash drive or external drive. Have the drive's cable or adapter if it uses one.

Before you begin: Save and close the file you want to copy. For a folder, close any files open from inside it. Copying leaves the original in its current folder. These steps copy one file or folder at a time.

1. Click Finder (the blue smiling face) in the Dock, the row of app icons along the edge of the screen.
2. In the menu bar at the top of the screen, click Go, then Computer.
3. Connect the external drive to the Mac. Connect the drive's power supply if it has one. If the Mac asks whether to allow this new accessory to connect, click Allow.
4. Wait for the drive to appear in the Computer window and remember its name. If no new drive appears, stop here. If a message says the disk is not readable by this computer, click Ignore and stop here. Do not click Initialize, because it erases the drive.
5. Click Go at the top of the screen, then the folder where you keep the file, such as Documents or Downloads. Open a folder inside it by clicking that folder twice quickly. Continue until you see the file you want.
6. Click the file or folder once. Click Edit at the top of the screen, then Copy followed by the selected item's name.
7. Click Go, then Computer, and double-click the external drive you identified in step 4.
8. Click Edit, then Paste Item. If asked to replace an existing item, click Stop to keep it, then go to step 10 to disconnect the drive.
9. Leave the drive connected until copying finishes. Check that the copied item appears on the drive.
10. Click Go, then Computer. Click your external drive once, then click File and Eject followed by the drive's name.
11. Wait for the drive to disappear from the Computer window, then unplug it. If the Mac says the drive is in use, leave it connected, wait one minute, then repeat step 10. If the message appears again, leave the drive connected and unplug it only after you next turn off the Mac.

Expected result: A copy of your file or folder is on the drive. The original remains in its previous folder.