01
Confirm the path is the cause
Error 0x800700CE and the message about the file name being too long are unambiguous. If the error mentions access instead, the problem is permissions and this guide will not help.
Enable **LongPathsEnabled** through group policy or the registry, then confirm the app supports it. Explorer, robocopy and modern build tools do; older installers still fail and need a shorter root folder.
Requirements
- Admin rights
- Windows 10 1607 or newer
- A copy of the affected folder
Instructions
02
Enable the policy
In the local group policy editor open the filesystem node and enable long paths. Without gpedit, set the registry value directly - both write the same switch.
Computer Configuration > Administrative Templates > System > Filesystem > Enable Win32 long paths
03
Set the registry value if there is no gpedit
Windows Home has no policy editor. Create a DWORD under the filesystem key with the value 1; a reboot makes it effective for every new process.
HKLM\YSTEM\urrentControlSet\ontrol\ileSystem
LongPathsEnabled = 1 (DWORD)⚠ warningThe setting is read when a process starts. Apps already running keep the old behaviour until you restart them.
04
Remember the app has a say too
The policy lifts the limit for programs whose manifest opts in. Explorer, PowerShell 7, robocopy, .NET 4.6.2 and newer handle long paths; a 2012 installer unpacks into the same wall it always did.
tiprobocopy works around the limit even without the policy. It is the fallback when an older app refuses.
05
Find the offenders before they bite
List every path above 240 characters so you know which folder needs flattening. A build output three levels deeper than the project root is the usual suspect.
Get-ChildItem -Recurse | Where-Object { $_.FullName.Length -gt 240 } | Select-Object -First 20 FullName
06
Keep the next project shallow
Copy into **C: mp** or **C:\rc**, work there and move the result afterwards. No policy setting fixes a tool that never asked Windows for the long path API.
Common issues
The registry value is set but nothing changed
Reboot, then retry with a freshly started app. The flag is read at process start.
Group policy keeps resetting the value
A domain policy is stronger than the local setting. Check with gpresult which policy wins.
It fails on a network share
UNC paths have their own limit unless both ends opt in. Copy locally, then sync the result to the share.
An archive extracts with truncated names
The extractor predates long path support. Extract to a short path and move the folder afterwards.
Frequently asked
Is enabling long paths safe?
Yes. It is backwards compatible; anything that does not opt in behaves exactly as before.
Does it affect every program?
No. Only programs that declare support in their manifest, which covers most current tools.
How to undo this
Set **LongPathsEnabled** back to 0 and reboot. Files that already exist with long names stay readable through the same apps that created them.
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- 2026-10-31First version
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