Copying .mov files to MS-DOS (FAT32) drives

I'm not sure if this is the right forum, but here's my problem: I tried to copy a .mov file for a client onto a MS-DOS (FAT32) drive so she can see it on her PC. I got this error code: "The operation can’t be completed because an unexpected error occurred (error code 0)."
The file copies fine onto a Mac OS Extended (Journaled)-formatted drive, but her PC doesn't see it.
Solutions?
Thanks.