Windows 10’s anniversary update brings an interesting if obscure change to the OS. Right now, long NFS filenames max out at 260 characters. The change busts through that limit and may eliminate it altogether. This limit includes the path specification and the filename itself, so 260 characters isn’t terribly generous. Consider these filenames, for example:
Where did I get them? Scrolling through the WinSxS folder for system files, I picked the biggest ones I could find. (Just for the record, the longest is 98 characters.) If I looked harder, I’m sure I could find longer. Adding a long path into the mix, it’s easy to see how the 260 character limit becomes a constraint.
Here’s the Enable NTFS long paths pane from the Local Group Policy Editor in Windows 10 1607 Build 14393.5
But a new Local Group Policy Editor setting for NTFS long paths lifts this ceiling. Simply click the radio button labeled “Enabled” as shown. For more details see TenForums.com principal and Windows 10 MVP Shawn Brink’s great tutorial. It’s entitled “How to Enable or Disable NTFS Long Paths in Windows 10.”
When the Ceiling on Long NTFS Filenames Is Raised…
I’m surprised that the default setting remains “Not Configured,” though. That’s because Windows itself uses the longest filenames I could find. But perhaps that’s a change for a future Windows update? In the meantime, Win32 applications must also change to accommodate such filenames. Ultimately, this kills a long-standing Windows certification question about filename length limitations.