Windows: What is Junction Point

What is Windows Junction Point

• what's windows junction
• https://x.com/i/grok/share/Oi53xHLuGtd9LsajmJZs2mi1o

A Windows junction (also called a directory junction or NTFS junction point) is a feature of the NTFS file system in Windows that acts like a shortcut or link for entire directories (folders). It allows you to make one folder appear to be located in multiple places on your drive, while actually pointing to a single real folder on disk.

Key characteristics of a Windows junction

Feature	Description
Type	Directory link (not a file link)
Introduced in	Windows 2000 (using NTFS)
Created with	mklink /J command (or tools like Link Shell Extension)
Looks like	A normal folder in Explorer (shows a shortcut overlay arrow in some views)
Transparent to apps	Most programs think it's a real folder and follow it automatically
Can point to	Local or network drives (as long as the target is accessible)
Cannot be created to	Non-NTFS volumes (FAT32, exFAT, etc.) or removable drives in some cases
Survives reboots	Yes
Relative paths allowed	Yes

How to create a junction (example)

Open Command Prompt or PowerShell as Administrator and run:

cmd
mklink /J "C:\LinkFolder" "D:\RealFolder"

This creates a junction at C:\LinkFolder that points to the real folder D:\RealFolder. Anything you read or write inside C:\LinkFolder actually happens in D:\RealFolder.

Difference from similar things

Type	Command	What it links	Shows arrow in Explorer	Can cross drives	Can be relative
Symbolic link	mklink /D	Folder	Yes	Yes	Yes
Junction	mklink /J	Folder	Sometimes (depends)	Yes	Yes
Hard link	mklink /H	File only	No	No	No
Shortcut (.lnk)	Right-click → New	File or folder	Yes	Yes	Yes

Main practical differences:

• Junctions are older, more compatible with very old software, and don’t allow linking to remote/non-existent targets when created.
• Directory symbolic links (/D) are newer (Vista+), more flexible, but some ancient programs or backup tools still have problems with them.

Common uses

• Moving large folders (e.g., Users, ProgramData, Steam games) to another drive while keeping the original path working.
• Organizing data without duplicating it.
• Redirecting default Windows folders (Documents, Downloads, etc.) to another disk.

How to identify a junction

In Command Prompt:

cmd
dir /AL

Junctions show up as <JUNCTION> in the listing.

In PowerShell:

powershell
Get-Item "C:\SomeFolder" | Select-Object LinkType, Target

So in short: a Windows junction is a transparent, NTFS-based redirect for folders, created with mklink /J, widely used for relocating big directories without breaking programs.

• NTFS junction point

Junction points (Microsoft documentation)

• https://learn.microsoft.com/en-us/windows/win32/vss/junction-points

Junction Command Line Tool by Mark Russinovich

• https://learn.microsoft.com/en-us/sysinternals/downloads/junction

• why is Junction v1.07 By Mark Russinovich created when mklink /J exist
• https://x.com/i/grok/share/vithFQ51iw0a1eo5tGDuKjkw4