How do I transfer a file from a guest account on a MacBook Air?

Solution 1:

Every user account on OS X has a public drop box folder inside its Public folder (path is /Users/USERNAME/Public/Drop\ Box/). So what you can do is download the file into Guest's Download folder and then copy it (via Terminal or Finder) to /Users/ADMINNAME/Public/Drop\ Box/. You will get a warning about not being able to access the file after the copy, just click ok there.

Alternatively you could move the video to /tmp and then switch accounts. Files owned by guest are not deleted from /tmp if the Guest user logs out.

Solution 2:

Copy file to USB external disk is the common way, you open Disk Utility app to check what's going on.

there are some other way to transfer large file

1. Airdrop
2. transfer file to AFP or SMB sharing
3. burning DVD
4. Target Disk Mode