Windows Hard Link Guide

Most Windows users think a file exists in exactly one place. Double-click a file in C:\Documents\Report.docx , and you assume that's the only copy on disk.

Workaround: Use directory junctions or symlinks with mklink /D or mklink /J . Hard links cannot span drives (C:\ to D:). Each volume maintains its own file reference table. For cross-volume needs, use symbolic links. ❌ The Deletion Trap This is the most common hard link mistake:

copy file.txt file_backup.txt # Wrong: uses 2x space mklink /H file_backup.txt file.txt # Right: zero extra space This is not a true snapshot. Changes to file.txt will appear in file_backup.txt because they're the same data. Use this only when you want simultaneous updates across paths, not historical versions. 3. Compatibility Layers for Legacy Software Some old software expects configuration files in hardcoded paths. Instead of copying (and then desyncing), use hard links:

echo Hello > original.txt mklink /H link.txt original.txt type link.txt # Output: Hello echo World >> original.txt type link.txt # Output: Hello World /H is the crucial flag—without it, mklink creates a symbolic link by default. New-Item -ItemType HardLink -Path "C:\links\link.txt" -Target "C:\data\original.txt" Or with the shorter alias:

But Windows has a secret: the . With a hard link, a single file can appear in multiple folders simultaneously, without duplicating any data. Change one, and the others update instantly. Delete one, and the others remain untouched.