A drive can show plenty of free space and still reject one large file. Free capacity answers how much storage remains overall; the file system can impose a separate limit on an individual file. Repeatedly deleting small folders will not resolve that second kind of restriction.
Check the exact error and inspect the drive's current format using the operating system's information or disk-management tools. Microsoft's file-system comparison lists a roughly 4 GiB single-file limit for FAT32. A video file larger than that limit can therefore fail to copy even when the drive has far more free space. Do not generalise that example into a diagnosis for every failed transfer: permissions, damage and connection problems can produce other errors.
Work out who must read the drive
Write down every intended device, including a camera, television or older computer if relevant. Apple's Disk Utility documentation lists FAT and ExFAT among Windows-compatible formats, but compatibility with a computer does not establish compatibility with every appliance. The receiving device's manual should determine the acceptable choices.
Also check whether the drive serves a dedicated function such as an application-managed backup. That function may have its own format requirements. A format suitable for sharing a large video file may be unsuitable for the backup process you already use. If the jobs conflict, separate drives can be simpler than repeatedly reformatting one device.
Preserve the files before changing anything
Formatting is not a harmless preference switch. Make a separate verified copy of all required contents before proceeding. Open several copied files and confirm that you know where the rest are. If you cannot make that copy, stop; the lack of another destination is a reason to postpone the change, not a reason to risk the only originals.
Identify the target drive by model, capacity and connection before using an erase or format command. Disconnect unrelated removable drives if doing so makes the choice clearer. Follow the operating system's instructions and read the confirmation carefully. Do not select a device simply because it appears in the position occupied by it yesterday.
After formatting, copy a disposable test file representative of your largest normal item. Open it on the receiving device, then test a smaller document that you can modify and save if writing is required. Only restore the full collection once the intended workflow works.
If changing the format is not an option
Ask whether the recipient can use another approved transfer method or another storage device. Splitting an archive may be possible in some workflows, but it also requires the recipient to reassemble it and may not suit a device that expects one playable file. Do not change an original video merely to fit a storage limitation without preserving its source.
Keep a note of the chosen format and its intended uses with the drive inventory. That small record prevents the same problem from reappearing when someone later borrows the drive for a different purpose.
A concrete capacity check
Imagine a drive with 40 GB free and a single video of roughly 6 GB. On a format with an individual-file limit below that video size, the available 40 GB does not solve the problem. By contrast, a folder of many smaller files with the same total size may fit. That contrast helps you recognise why the error can appear inconsistent without assuming the drive has suddenly lost capacity.
Now add a television that supports only a limited set of storage formats and video types. Changing the drive format might solve the computer's copy problem while making the television unable to read it. Even a readable drive may contain a video encoding the television cannot play. Keep those three questions separate: can the file be stored, can the device read the storage and can its player interpret the video?
