How do I enable paths longer than 260 characters?

How do I enable paths longer than 260 characters?

In days of yore, filenames in Windows were limited to the 8.3 format -- just eight characters for the filename, and three for the extension. With the arrival of Windows 95, Microsoft stripped away this limit and allowed for much longer names.

That said, the Windows file system still imposes some restrictions such as which characters can be used in filenames, and the overall length of paths. For some time the maximum path length has been 260 characters, but in the latest Windows 10 Insider Preview, it is possible to use Group Policy or a registry hack to remove this limit.

It's not a feature that will work with every application you have installed, but it should work with many. As Microsoft's description of the feature explains: "Enabling NTFS long paths will allow manifested win32 applications and Windows Store applications to access paths beyond the normal 260 char limit per node. Enabling this setting will cause the long paths to be accessible within the process."

It's likely that this feature will be made available in Windows 10 Anniversary Update when it is released later in the year, but you can enable it in the latest Insider build using Group Policy:

  1. Hit the Windows key, type gpedit.msc and press Enter.
  2. Navigate to Local Computer Policy > Computer Configuration > Administrative Templates > System > Filesystem > NTFS.
  3. Double click the Enable NTFS long paths option and enable it.

If you're using a version of Windows that does not provide access to Group Policy, you can edit the registry instead.

  1. Hit the Windows key, type regedit and press Enter.
  2. Navigate to HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\ CurrentVersion\Group Policy Objects\ {48981759-12F2-42A6-A048-028B3973495F} Machine\System\CurrentControlSet\Policies
  3. Select the LongPathsEnabled key, or create it as a DWORD (32-bit) value if it does not exist.
  4. Set the value to 1 and close the Registry Editor.

Hat tip to Martin for this!

Photo credit: Modella / Shutterstock

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Maximum Path Length Limitation

  • Article
  • 07/18/2022
  • 4 minutes to read

In this article

In the Windows API (with some exceptions discussed in the following paragraphs), the maximum length for a path is MAX_PATH, which is defined as 260 characters. A local path is structured in the following order: drive letter, colon, backslash, name components separated by backslashes, and a terminating null character. For example, the maximum path on drive D is "D:\some 256-character path string" where "" represents the invisible terminating null character for the current system codepage. (The characters < > are used here for visual clarity and cannot be part of a valid path string.)

For example, you may hit this limitation if you are cloning a git repo that has long file names into a folder that itself has a long name.

Note

File I/O functions in the Windows API convert "/" to "\" as part of converting the name to an NT-style name, except when using the "\\?\" prefix as detailed in the following sections.

The Windows API has many functions that also have Unicode versions to permit an extended-length path for a maximum total path length of 32,767 characters. This type of path is composed of components separated by backslashes, each up to the value returned in the lpMaximumComponentLength parameter of the GetVolumeInformation function (this value is commonly 255 characters). To specify an extended-length path, use the "\\?\" prefix. For example, "\\?\D:\very long path".

Note

The maximum path of 32,767 characters is approximate, because the "\\?\" prefix may be expanded to a longer string by the system at run time, and this expansion applies to the total length.

The "\\?\" prefix can also be used with paths constructed according to the universal naming convention (UNC). To specify such a path using UNC, use the "\\?\UNC\" prefix. For example, "\\?\UNC\server\share", where "server" is the name of the computer and "share" is the name of the shared folder. These prefixes are not used as part of the path itself. They indicate that the path should be passed to the system with minimal modification, which means that you cannot use forward slashes to represent path separators, or a period to represent the current directory, or double dots to represent the parent directory. Because you cannot use the "\\?\" prefix with a relative path, relative paths are always limited to a total of MAX_PATH characters.

There is no need to perform any Unicode normalization on path and file name strings for use by the Windows file I/O API functions because the file system treats path and file names as an opaque sequence of WCHARs. Any normalization that your application requires should be performed with this in mind, external of any calls to related Windows file I/O API functions.

When using an API to create a directory, the specified path cannot be so long that you cannot append an 8.3 file name (that is, the directory name cannot exceed MAX_PATH minus 12).

The shell and the file system have different requirements. It is possible to create a path with the Windows API that the shell user interface is not able to interpret properly.

Enable Long Paths in Windows 10, Version 1607, and Later

Starting in Windows 10, version 1607, MAX_PATH limitations have been removed from common Win32 file and directory functions. However, you must opt-in to the new behavior.

To enable the new long path behavior, both of the following conditions must be met:

  • The registry key Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem\LongPathsEnabled (Type: REG_DWORD) must exist and be set to 1. The key's value will be cached by the system (per process) after the first call to an affected Win32 file or directory function (see below for the list of functions). The registry key will not be reloaded during the lifetime of the process. In order for all apps on the system to recognize the value of the key, a reboot might be required because some processes may have started before the key was set.

You can also copy this code to a .reg file which can set this for you, or use the PowerShell command from a terminal window with elevated privileges:

  • Registry (.reg) file
  • PowerShell
Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem]
"LongPathsEnabled"=dword:00000001

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

Note

This registry key can also be controlled via Group Policy at Computer Configuration > Administrative Templates > System > Filesystem > Enable Win32 long paths.

  • The application manifest must also include the longPathAware element.

    
        
            true
        
    
    

These are the directory management functions that no longer have MAX_PATH restrictions if you opt-in to long path behavior: CreateDirectoryW, CreateDirectoryExW GetCurrentDirectoryW RemoveDirectoryW SetCurrentDirectoryW.

These are the file management functions that no longer have MAX_PATH restrictions if you opt-in to long path behavior: CopyFileW, CopyFile2, CopyFileExW, CreateFileW, CreateFile2, CreateHardLinkW, CreateSymbolicLinkW, DeleteFileW, FindFirstFileW, FindFirstFileExW, FindNextFileW, GetFileAttributesW, GetFileAttributesExW, SetFileAttributesW, GetFullPathNameW, GetLongPathNameW, MoveFileW, MoveFileExW, MoveFileWithProgressW, ReplaceFileW, SearchPathW, FindFirstFileNameW, FindNextFileNameW, FindFirstStreamW, FindNextStreamW, GetCompressedFileSizeW, GetFinalPathNameByHandleW.