The source file name(s) are larger than is supported by the file system

Windows adds “Try moving to a location which has a shorter path name, or try renaming to shorter name(s) before attempting this operation.” This is Windows saying a path is too long to work with.

What it means

Windows has an old limit called MAX_PATH. It is 260 characters for a full path. That count includes the drive letter, the colon, the backslashes, the name parts and one hidden ending character.

A folder like node_modules nests packages inside packages. The path can pass 260 characters easily, and then File Explorer and many programs cannot open, move or delete the files inside.

Why it happens

Deep folders, for example node_modules inside node_modules inside a project that already sits in a long path.
Cloning a repo with long file names into a folder that itself has a long name. Microsoft names this exact case in its own guide.
A program that was written before long paths were supported.

Windows 10 version 1607 and later can remove the limit, but two things must be true. The registry value LongPathsEnabled must be 1, and the program must declare that it supports long paths. Many do not, so turning the setting on is not a full fix.

How Devpit fixes or avoids it

Free Up Disk Space removes folders with its own code, not with Explorer. If a delete fails because the path is over the limit, Devpit tries again with the extended-length form of the path, the one that starts with \\?\. That form tells Windows to skip the 260 character check.

If something still cannot be removed, Devpit does not hide it. It puts the folder in the summary with a reason so you can act.

The manual fix

Try these from the simplest to the most technical.

1. Shorten the path. Rename a parent folder to a shorter name, or move the folder up to something like C:\p. Then delete it.

2. Delete it with rmdir. /s removes the whole tree and /q skips the confirmation:

rd /s /q "C:\path\to\node_modules"

rd is the short name of rmdir. Check the path first, because /q does not ask.

3. Turn on long paths. Run this in PowerShell as administrator, then restart Windows if programs still fail. Microsoft says a restart might be needed because some processes started before the key was set:

New-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\FileSystem" `
  -Name "LongPathsEnabled" -Value 1 -PropertyType DWORD -Force

4. Empty the folder with robocopy. /MIR mirrors a source into a destination and deletes destination files that are not in the source. If the source is an empty folder, everything in the destination is deleted:

mkdir C:\empty
robocopy C:\empty "C:\path\to\node_modules" /MIR
rmdir "C:\path\to\node_modules"
rmdir C:\empty

The first path is the empty source and the second is the folder to empty. If you swap them, robocopy copies instead of deleting. Microsoft’s pages describe /MIR but do not describe this delete trick by name. It is a widely used use of that documented behaviour. When robocopy ends, its exit code tells you how it went: see robocopy exit codes.

Sources

Common questions

What is the maximum path length on Windows?

In the classic Windows API the limit is MAX_PATH, which is 260 characters including the drive letter and a final null character. Paths in the extended form that starts with \\?\ can be about 32,767 characters.

Does turning on LongPathsEnabled fix it for every program?

No. Microsoft says the registry value only affects applications that have opted in with a longPathAware entry in their manifest. Some programs will still hit the 260 character limit.

Is the robocopy empty folder trick safe?

It is safe if you type the folders in the right order. The first folder is the empty source and the second is the folder you want to empty. If you swap them you copy files instead of deleting them, so read the command twice.