C Drive Full: Create a SYMLINK

Guide on how to move heavy folders (like Apple Backups, Steam Games, or Chrome Cache) to a secondary drive while tricking Windows into thinking they are still on the C: drive.

What is a Symlink?

A Symbolic Link (specifically a Junction Point for folders) acts like a shortcut, but deeper. Applications treat it as if the folder is really there.

• Real Location: D:\MovedStuff\MyFolder
• Fake Location: C:\Program Files\MyFolder

When a program writes to the C: drive, Windows transparently redirects it to the D: drive.

Step-by-Step Guide

Scenario: Moving iPhone Backups to the D: Drive

iTunes stores backups in %APPDATA%\Apple Computer\MobileSync\Backup, which can take up 100GB+.

1. Locate the Folder Find the folder you want to move. Source: C:\Users\Bas\AppData\Roaming\Apple Computer\MobileSync\Backup

2. Move the Folder

   • Cut (Ctrl+X) the Backup folder.
   • Paste (Ctrl+V) it to your secondary drive, e.g., D:\iTunesBackup.

3. Open Command Prompt

   • Press Win + R, type cmd, press Enter.
   • (Or search for Command Prompt and select "Run as Administrator").

4. Create the Link Use the mklink command with the /J (Junction) flag.

   Syntax:

   mklink /J "Link Location" "Real Target"

   Example:

   mklink /J "C:\Users\Bas\AppData\Roaming\Apple Computer\MobileSync\Backup" "D:\iTunesBackup"

5. Verify

   • You will see a folder icon with a small shortcut arrow in the C: drive location.
   • If you double-click it, you enter the folder, but the files are physically stored on the D: drive.

Common Use Cases

Steam Games

Move C:\Program Files (x86)\Steam\steamapps\common to D:\Games.

Chrome/Spotify Cache

Move AppData\Local\Google\Chrome\User Data to save SSD wear.

User Downloads

Move C:\Users\Name\Downloads to a larger HDD.

Important Notes

• Delete Original: You must delete (or move/rename) the original folder on the C: drive before creating the link, otherwise mklink will say "Cannot create a file when that file already exists".
• Quotes: Always use "quotes" if your path contains spaces.
• Admin Rights: Writing to C:\Program Files requires Command Prompt to be run as Administrator.