Using SUBST to Create Virtual Drives in Windows

Ever wish you could turn a long, annoying folder path into its own drive letter — instantly?

Good news: Windows has had a secret command for that since the stone age (aka DOS). It’s called SUBST, and it lets you create a virtual drive letter for any local folder. Think of it as a symbolic link’s chill, drive-mapping cousin.

What Is `SUBST`?

SUBST stands for “substitute”, and it lets you assign a drive letter to a local path.
It doesn’t move or duplicate anything — it just maps a folder as if it were a separate drive.

You know that 100-character-long C:\Users\Zaur\Projects\SuperImportant\StuffToDemo path?
You can turn it into Z:\ in one line.

Basic Syntax

cmd

SUBST <DriveLetter>: <FolderPath>

Example:

cmd

SUBST Z: "C:\scripts"

Now you can access Z:\ in Explorer, Command Prompt, or any app — and it will point to that long path.

How to Remove a SUBST Drive

cmd

SUBST Z: /D

Boom. The drive disappears. No files deleted. Nothing moved. It’s like it never happened.

See All Current Mappings

cmd

SUBST

This lists all current virtual drives created with SUBST.

Why Use It?

Common Use Cases:

Shorten long, deep file paths for easier navigation
Simplify dev environments (e.g. set W:\ for your web root)
Help legacy apps that expect to run from a drive root
Create throwaway drives for testing installs, scripts, or tools

Caveats to Know

Mappings made with SUBST do not persist after reboot unless added via script or registry
SUBST drives behave like local drives in Explorer, but some software (especially older ones) might not fully support them
Doesn’t work with network shares — only local paths

Pro Tip: Make It Persistent

To keep your SUBST drive alive after reboot:

Option 1: Add it to a startup script (Task Scheduler or Startup folder)

cmd

SUBST Z: "C:\Path\To\Folder"

Option 2: Use the Registry (manual but reliable)

Add under:

regedit

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\DOS Devices

Add a new String Value:

Name: Z:
Data: \??\C:\Path\To\Folder

⚠️ Note: The \??\ prefix is important — it tells Windows this is a symbolic path.

To Remove the Mapping

Go back to the same registry key
Delete the string value (e.g. Z:)
Reboot

Extra Notes

Thing	Detail
Drives created this way	Show up like real drives
Still point to folders	No duplication — just a redirected path
Affects all users	Since it’s under `HKLM`
Requires admin rights	Yes — it’s editing system-wide settings

In a nutshell:

Command	What it does
`SUBST Z: C:\Folder`	Maps folder to a virtual drive
`SUBST`	Lists all current mappings
`SUBST Z: /D`	Deletes the mapping
Registry + DOS Devices	Makes the mapping persistent on reboot

Final Thoughts

SUBST might not be flashy, but it’s a lightweight tool that can seriously declutter your daily workflow. Whether you’re coding, scripting, or just sick of typing long paths, it’s a shortcut worth remembering.

Got a favorite SUBST trick or using it in your workflow? Drop a comment — or stay tuned for a post on net use and mapping network drives the smart way. 😉

What Is SUBST?