cheat sheet

mountvol

List, create, and remove NTFS volume mount points and display the unique volume GUID path for any drive letter or directory junction from the command prompt.

updated 05-26-2026

mountvol — Volume Mount Point Manager

What it is

mountvol is a built-in Windows command for listing all mounted volumes and managing NTFS volume mount points — the ability to attach a volume at an arbitrary directory path rather than a drive letter. A volume mounted at C:\Data\Archive is accessible through the path just like a folder, while consuming no drive letter. Use it to expose volumes with GUID paths in scripts, create or remove directory mount points, and list which GUID corresponds to which volume. The PowerShell equivalent is Get-Volume and Add-PartitionAccessPath.

Availability

mountvol ships as C:\Windows\System32\mountvol.exe on Windows 2000 and later. Creating or removing mount points requires Administrator privileges and an NTFS target directory.

cmd

mountvol /?

Output:

less

Creates, deletes, or lists a volume mount point.

MOUNTVOL [drive:]path VolumeName
MOUNTVOL [drive:]path /D
MOUNTVOL [drive:]path /L
MOUNTVOL [drive:]path /P
MOUNTVOL /R
MOUNTVOL /N
MOUNTVOL /E
MOUNTVOL drive: /S

  path        Specifies the existing NTFS directory where the mount
              point will reside.
  VolumeName  Specifies the volume name that is the target of the
              mount point.
  /D          Removes the volume mount point from the specified directory.
  /L          Lists the mounted volume name for the specified directory.
  /P          Removes the volume mount point from the specified directory,
              dismounts the volume, and makes the volume not mountable.
              You can make the volume mountable again by creating a volume
              mount point.
  /R          Removes volume mount point directories and registry settings
              for volumes that are no longer in the system.
  /N          Disables automatic mounting of new volumes.
  /E          Re-enables automatic mounting of new volumes.
  /S          Mount the EFI system partition on the given drive.

Syntax

cmd

mountvol [path] [VolumeName | /D | /L | /P]
mountvol /R | /N | /E

Output: (volume list or operation result)

Essential options

Switch	Meaning
(no args)	List all volumes with their drive letter and GUID path
`path VolumeName`	Mount the volume (GUID path) at the given directory
`path /D`	Remove the mount point at the given directory
`path /L`	Show the volume GUID for the path
`path /P`	Remove the mount point and dismount the volume
`/R`	Clean up stale mount point entries for removed volumes
`/N`	Disable automatic drive-letter assignment for new volumes
`/E`	Re-enable automatic drive-letter assignment
`drive: /S`	Mount the EFI system partition at the drive letter

Listing all volumes

Running mountvol with no arguments lists every volume visible to Windows with its current drive letter (if assigned) and its GUID path. The GUID path is the canonical reference that survives drive-letter reassignment.

cmd

mountvol

Output:

sql

Possible values for VolumeName along with current mount points are:

    \\?\Volume{a1b2c3d4-e5f6-7890-abcd-ef1234567890}\
        C:\

    \\?\Volume{f0e1d2c3-b4a5-6789-fedc-ba9876543210}\
        D:\

    \\?\Volume{01234567-89ab-cdef-0123-456789abcdef}\
        *** NO MOUNT POINTS ***

Querying a volume's GUID path (/L)

/L returns the GUID path for the volume mounted at a given drive letter or directory. This is useful in scripts that need to pass a stable volume reference to chkdsk, fsutil, or diskpart.

cmd

mountvol C: /L

Output:

ruby

\\?\Volume{a1b2c3d4-e5f6-7890-abcd-ef1234567890}\

Creating a directory mount point

To mount a volume at a directory, provide the target path (which must be an empty NTFS folder) and the volume GUID path. After mounting, the directory transparently exposes the volume's contents.

cmd

rem Create the mount directory
mkdir C:\Data\Archive

rem Mount the volume at the directory
mountvol C:\Data\Archive \\?\Volume{f0e1d2c3-b4a5-6789-fedc-ba9876543210}\

Output:

csharp

(none — exits 0 on success)

cmd

rem Verify the mount point exists
mountvol C:\Data\Archive /L

Output:

ruby

\\?\Volume{f0e1d2c3-b4a5-6789-fedc-ba9876543210}\

Removing a mount point (/D)

/D detaches the volume from the directory mount point but leaves the volume intact and its data accessible by other means (such as a drive letter). The directory remains after removal.

cmd

mountvol C:\Data\Archive /D

Output:

csharp

(none — exits 0 on success)

Dismounting and preventing remount (/P)

/P removes the mount point, dismounts the volume, and marks it as not auto-mountable. Use this before physically hot-swapping a drive or before passing a disk to a backup job that needs exclusive access. Run mountvol C:\Data\Archive <GUID> afterward to make it accessible again.

cmd

mountvol C:\Data\Archive /P

Output:

csharp

(none — exits 0 on success)

Controlling automount (/N and /E)

By default Windows automatically assigns a drive letter whenever a new volume is attached. /N disables this behavior — useful on servers where unknown external drives should not appear automatically. /E restores the default.

cmd

rem Disable auto-mount (server hardening)
mountvol /N

Output:

csharp

(none — exits 0 on success)

cmd

rem Re-enable auto-mount
mountvol /E

Output:

csharp

(none — exits 0 on success)

How a mount point actually works

A volume mount point is an NTFS reparse point with the directory junction tag (0xA0000003) whose payload is a substitute volume GUID path. When any file API touches the directory, the I/O Manager translates the path through the reparse data and redirects the operation to the target volume's root. The behaviour is transparent to applications — dir C:\Data\Archive reads the mounted volume's root just like any other folder.

cmd

rem Confirm a mount-point folder is a reparse point
fsutil reparsepoint query C:\Data\Archive

Output:

yaml

Reparse Tag Value : 0xa0000003
Tag value: Microsoft
Tag value: Name Surrogate
Tag value: Mount Point
Reparse Data Length: 0x0000004c
Reparse Data:
0000:  46 00 48 00 00 00 48 00  5c 00 3f 00 3f 00 5c 00  F.H...H.\.?.?.\.
0010:  56 00 6f 00 6c 00 75 00  6d 00 65 00 7b 00 66 00  V.o.l.u.m.e.{.f.
0020:  30 00 65 00 31 00 64 00  32 00 63 00 33 00 2d 00  0.e.1.d.2.c.3.-.
...

Because the mount point is a reparse point, fsutil reparsepoint delete is an equivalent way to remove the mount — but it leaves the directory entry empty and intact, just like mountvol /D.

Drive letters vs mount points vs GUID paths

A single volume can be reached through up to three classes of access paths at the same time:

Access path	Example	Persistent?	Stable across reboots?
Drive letter	`D:\`	Yes (in `MountedDevices` registry key)	Yes, unless drive letter is reassigned.
Directory mount point	`C:\Data\Archive\`	Yes (NTFS reparse data on the directory)	Yes, even if drive letter changes.
Volume GUID path	`\\?\Volume{f0e1d2c3-...}\`	Yes (assigned at volume creation)	Yes, including across hardware swaps that preserve the volume.

The GUID path is the truly stable identifier — it survives drive-letter reassignment and even moving the disk to a different machine. Scripts that reference volumes by drive letter break when letters are reshuffled; scripts using the GUID path don't.

cmd

rem Get the GUID for D: and use it in a way that survives D: being remapped
for /f "tokens=* delims= " %V in ('mountvol D: /L') do set VOL=%V
echo Volume: %VOL%

rem Pass the GUID directly to other tools
chkdsk %VOL% /scan

Output:

csharp

Volume: \\?\Volume{f0e1d2c3-b4a5-6789-fedc-ba9876543210}\
The type of the file system is NTFS.
Stage 1: Examining basic file system structure ...
Stage 2: Examining file name linkage ...
Stage 3: Examining security descriptors ...
Stage 4: Looking for bad sectors in user file data ...
Windows has scanned the file system and found no problems.

EFI System Partition mounting (/S)

The EFI System Partition (ESP) is the FAT32 partition that the firmware reads to find the bootloader. By default it has no drive letter — Windows hides it from Explorer to prevent accidental modification. mountvol drive: /S is the supported way to mount it temporarily for inspection or bcdboot repair work.

cmd

rem Mount the ESP at S: (must be run from Administrator)
mountvol S: /S

Output:

csharp

(no output — exits 0 on success)

cmd

rem Now you can browse the ESP
dir S:\EFI\Microsoft\Boot

Output:

swift

 Directory of S:\EFI\Microsoft\Boot

01/01/2026  09:15    <DIR>          .
01/01/2026  09:15    <DIR>          ..
01/01/2026  09:15            27,648 BCD
01/01/2026  09:15            65,536 BCD.LOG
01/01/2026  09:15           212,496 bootmgfw.efi
01/01/2026  09:15           212,496 bootmgr.efi
01/01/2026  09:15    <DIR>          en-US
01/01/2026  09:15    <DIR>          Fonts
01/01/2026  09:15    <DIR>          Resources

cmd

rem Done — remove the assignment (does NOT dismount the underlying volume)
mountvol S: /D

Output:

csharp

(no output — exits 0 on success)

If bcdedit is the boot-store editor, mountvol /S is how you put the boot store on disk so bcdedit can find it from a maintenance OS. See sections/windows/bcdedit.

PowerShell equivalents

PowerShell's Storage module covers the same workflows in object-returning cmdlets.

`mountvol` operation	PowerShell
List all volumes	`Get-Volume` or `Get-Partition
Show GUID path for a drive	`(Get-Volume X).Path` or `(Get-Partition -DriveLetter X).AccessPaths`
Create directory mount	`Add-PartitionAccessPath -DiskNumber N -PartitionNumber M -AccessPath C:\Data\Archive`
Remove directory mount	`Remove-PartitionAccessPath -DiskNumber N -PartitionNumber M -AccessPath C:\Data\Archive`
Dismount volume	`Get-Disk N
Enable / disable automount	`Set-StorageSetting -NewDiskPolicy OnlineAll
Mount EFI System Partition	`Add-PartitionAccessPath -DiskNumber 0 -PartitionNumber 1 -AccessPath S:\`
Cleanup stale mounts	`Get-Partition

powershell

# List every volume and every path it's accessible through
Get-Partition | Where-Object { $_.AccessPaths -and $_.Type -ne 'Reserved' } |
    Select DiskNumber, PartitionNumber,
           @{n='Letter';e={ $_.DriveLetter }},
           @{n='Paths';e={ ($_.AccessPaths -join ', ') }}

Output:

ruby

DiskNumber PartitionNumber Letter Paths
---------- --------------- ------ -----
         0               2     C  C:\, \\?\Volume{a1b2c3d4-e5f6-7890-abcd-ef1234567890}\
         1               1     D  D:\, C:\Data\Archive\, \\?\Volume{f0e1d2c3-b4a5-6789-fedc-ba9876543210}\
         2               1            \\?\Volume{01234567-89ab-cdef-0123-456789abcdef}\

powershell

# Mount disk 1, partition 1 at C:\Data\Archive
Add-PartitionAccessPath -DiskNumber 1 -PartitionNumber 1 -AccessPath C:\Data\Archive

Output:

csharp

(no output on success)

powershell

# Remove a directory mount
Remove-PartitionAccessPath -DiskNumber 1 -PartitionNumber 1 -AccessPath C:\Data\Archive

Output:

csharp

(no output on success)

powershell

# Mount the EFI System Partition for inspection
Add-PartitionAccessPath -DiskNumber 0 -PartitionNumber 1 -AccessPath S:\

Output:

csharp

(no output on success)

powershell

# Resolve drive letter -> GUID path via Get-Volume
Get-Volume -DriveLetter D | Select DriveLetter, Path, FileSystemLabel, FileSystemType, Size, SizeRemaining

Output:

css

DriveLetter Path                                                  FileSystemLabel FileSystemType         Size SizeRemaining
----------- ----                                                  --------------- --------------         ---- -------------
D           \\?\Volume{f0e1d2c3-b4a5-6789-fedc-ba9876543210}\     Data            NTFS           2000398934016 905134669824

Mount-DiskImage for VHD/ISO

mountvol is for managing existing volume mount points; Mount-DiskImage is the PowerShell cmdlet that turns a .vhd, .vhdx, or .iso file into a mounted volume in the first place. After the image is mounted, mountvol lists it like any other volume.

powershell

# Mount an ISO and find its drive letter
$img = Mount-DiskImage -ImagePath D:\ISOs\Windows.iso -StorageType ISO -PassThru
$letter = ($img | Get-Volume).DriveLetter
"ISO mounted at ${letter}:"

Output:

yaml

ISO mounted at H:

powershell

# Mount a VHDX as read-write
Mount-DiskImage -ImagePath C:\VMs\lab.vhdx -StorageType VHDX -Access ReadWrite -PassThru |
    Get-Disk |
    Initialize-Disk -PartitionStyle GPT -PassThru |
    New-Partition -UseMaximumSize -DriveLetter Q |
    Format-Volume -FileSystem NTFS -NewFileSystemLabel 'Lab' -Confirm:$false

Output:

css

DriveLetter FileSystemLabel FileSystemType DriveType HealthStatus OperationalStatus SizeRemaining       Size
----------- --------------- -------------- --------- ------------ ----------------- -------------       ----
Q           Lab             NTFS           Fixed     Healthy      OK                49.93 GB          50.00 GB

powershell

# Dismount when finished
Dismount-DiskImage -ImagePath D:\ISOs\Windows.iso
Dismount-DiskImage -ImagePath C:\VMs\lab.vhdx

Output:

yaml

Attached  : False
ImagePath : D:\ISOs\Windows.iso

Attached  : False
ImagePath : C:\VMs\lab.vhdx

Persistent vs ephemeral mounts

A mountvol directory mount is persistent: it survives reboots because the reparse data on the host directory is part of the host volume's NTFS metadata. Auto-mounted drive letters (assigned by Windows when a removable drive is inserted) are also persistent — recorded in HKLM\SYSTEM\MountedDevices.

cmd

rem Inspect the persistence registry — every persistent mount is in here
reg query "HKLM\SYSTEM\MountedDevices" /s

Output:

markdown

HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices
    \??\Volume{a1b2c3d4-e5f6-7890-abcd-ef1234567890}    REG_BINARY    5C003F003F005C00...
    \DosDevices\C:    REG_BINARY    5C003F003F005C00...
    \DosDevices\D:    REG_BINARY    5C003F003F005C00...
    \DosDevices\E:    REG_BINARY    5C003F003F005C00...

cmd

rem Force Windows to forget a stale assignment (e.g. removed USB key still claiming a letter)
mountvol /R

Output:

csharp

(no output — exits 0 on success)

/R cleans up stale entries for volumes that no longer exist, freeing the letters they were squatting on.

Folder-redirected data layouts

A common server-room layout is a single OS drive (C:) with very fast SSD and one or more huge HDDs mounted under C:\Data rather than getting their own drive letters. This gives applications a single backup path tree, lets backups recurse into one folder, and keeps drive letters from getting cluttered.

cmd

@echo off
rem Standardize layout:
rem   C:                   - OS
rem   C:\Data\Archive  ->  Volume D: (HDD)
rem   C:\Data\Media    ->  Volume E: (HDD)
rem   C:\Data\Scratch  ->  Volume F: (NVMe)

mkdir C:\Data\Archive 2>NUL
mkdir C:\Data\Media   2>NUL
mkdir C:\Data\Scratch 2>NUL

for /f %V in ('mountvol D: /L') do set ARCH=%V
for /f %V in ('mountvol E: /L') do set MEDI=%V
for /f %V in ('mountvol F: /L') do set SCRT=%V

mountvol C:\Data\Archive %ARCH%
mountvol C:\Data\Media   %MEDI%
mountvol C:\Data\Scratch %SCRT%

rem Optional: remove the drive letters so the volumes are only reachable through C:\Data
mountvol D: /D
mountvol E: /D
mountvol F: /D

dir C:\Data

Output:

css

 Directory of C:\Data

05/25/2026  03:14 PM    <JUNCTION>     Archive [\\?\Volume{f0e1d2c3-b4a5-6789-fedc-ba9876543210}\]
05/25/2026  03:14 PM    <JUNCTION>     Media   [\\?\Volume{a2b3c4d5-e6f7-8901-bcde-fa1234567890}\]
05/25/2026  03:14 PM    <JUNCTION>     Scratch [\\?\Volume{b3c4d5e6-f708-9012-cdef-ab1234567890}\]
               3 Dir(s)  234,789,123,456 bytes free

Detecting and reporting volume health by GUID

When something fails on \\?\Volume{...}, the drive letter (if any) is often not in the error message. Reverse-resolve the GUID to find what's affected.

powershell

function Get-VolumeFromGuidPath {
    param([Parameter(Mandatory)][string]$Path)
    Get-Volume | Where-Object { $_.Path -eq $Path } |
        Select DriveLetter, FileSystemLabel, FileSystemType, HealthStatus,
               @{n='SizeGB';e={[math]::Round($_.Size/1GB,1)}},
               @{n='FreeGB';e={[math]::Round($_.SizeRemaining/1GB,1)}}
}

Get-VolumeFromGuidPath -Path '\\?\Volume{f0e1d2c3-b4a5-6789-fedc-ba9876543210}\'

Output:

yaml

DriveLetter     : D
FileSystemLabel : Data
FileSystemType  : NTFS
HealthStatus    : Healthy
SizeGB          : 1862.4
FreeGB          : 843.2

Cross-references: where mountvol fits in the toolchain

Tool	When to use
`mountvol`	List mounts, create/remove directory mount points, manage EFI mount.
`diskpart assign` / `Add-PartitionAccessPath`	Same operation, with extra options (size, letter, etc.). See `sections/windows/diskpart`.
`Mount-DiskImage` / `Dismount-DiskImage`	Mount ISO / VHD / VHDX files.
`fsutil reparsepoint query`	Inspect the underlying reparse data of a mount point. See `sections/windows/fsutil`.
`fsutil volume list`	List volume GUID paths.
`Get-Volume` / `Get-Partition`	Inventory with object output.
`chkdsk \\?\Volume{...}`	Run integrity check by GUID path. See `sections/windows/chkdsk`.
`bcdedit /enum`	Boot store editing once the EFI partition is mounted. See `sections/windows/bcdedit`.
`dism /Image:<mounted-vhd>`	Service mounted images by directory path. See `sections/windows/dism`.
`mklink /J path target`	Alternative junction that points to another directory, not a volume.

Common pitfalls

Target directory must be empty — mountvol fails if the target path contains any files; create a fresh empty folder and use that.
Target must be on an NTFS volume — FAT32 or exFAT directories cannot host mount points; the host volume (e.g. C:) must be NTFS.
Volume GUID path must end with a backslash — \\?\Volume{...}\ (trailing \) is required; omitting it returns "The filename, directory name, or volume label syntax is incorrect".
/D removes the mount point but not the folder — the empty directory remains and can be reused; delete it with rmdir if no longer needed.
Drive-letter assignments are unaffected by /P — if the volume also has a drive letter (e.g. D:), /P removes only the directory mount point; the drive letter persists until reassigned elsewhere.
mountvol /N is global — disabling automount affects every new disk, including USB sticks plugged in by the user; document the change in the build manifest.
The EFI System Partition mount is volatile — mountvol S: /S does not persist across reboots; remount it from WinRE every time you need it.
Deleting a mount-point folder with files inside deletes them on the target volume — Windows will warn, but if you confirm, the data inside the mounted volume is gone; always mountvol /D first.
Cross-volume operations don't cross mount points transparently for hard links — mklink /H only works within a single volume; a hard link from a host volume to a file inside a mounted child volume fails.
mountvol C:\Data\Archive with C: not NTFS fails silently with a misleading error — verify with fsutil fsinfo volumeinfo C: before troubleshooting other issues.
mountvol /R removes registry entries only for volumes Windows knows are gone — if a volume is offline rather than removed, /R leaves the entry in place; bring the disk back, then run /R.
The GUID path is case-sensitive in some APIs — copy/paste it rather than typing it; the surrounding braces and hyphens must match exactly.
Storage Spaces virtual disks present as ordinary volumes to mountvol — you can mount them at directory paths just like physical-disk volumes, but Repair-VirtualDisk is what restores resilience, not chkdsk.
Mounting a removable volume at a directory makes ejection unsafe via Explorer — Windows hides the "Safely Remove" option for the underlying drive once it's mounted; dismount with mountvol /P before ejecting.

Sources

References consulted while writing this article. Links open in a new tab.

Microsoft Learn — mountvol command reference — Authoritative flag list and parameter semantics used to build the Essential options table.
SS64 — mountvol — Cross-version comparison and historical syntax notes.

Real-world recipes

Mount a secondary volume under a data folder

cmd

@echo off
mkdir C:\Mounts\Backup 2>NUL
for /f %G in ('mountvol D: /L') do set GUID=%G
mountvol C:\Mounts\Backup %GUID%
echo Mounted D: at C:\Mounts\Backup

Output:

yaml

Mounted D: at C:\Mounts\Backup

List all volumes and their mount points

cmd

mountvol | findstr /V "Possible\|values\|VolumeName\|along\|^$"

Output:

ruby

    \\?\Volume{a1b2c3d4-e5f6-7890-abcd-ef1234567890}\
        C:\
    \\?\Volume{f0e1d2c3-b4a5-6789-fedc-ba9876543210}\
        D:\
    \\?\Volume{01234567-89ab-cdef-0123-456789abcdef}\
        *** NO MOUNT POINTS ***

Clean up stale mount point entries

cmd

mountvol /R
echo Stale mount point registry entries removed.

Output:

arduino

Stale mount point registry entries removed.

Bulk-mount data volumes by label

Rather than memorising drive letters, mount volumes by their NTFS labels into a known directory tree.

powershell

$mountRoot = 'C:\Mounts'
$pairs = @(
    @{ Label = 'Archive'; Path = "$mountRoot\Archive" },
    @{ Label = 'Media';   Path = "$mountRoot\Media"   },
    @{ Label = 'Scratch'; Path = "$mountRoot\Scratch" }
)

foreach ($pair in $pairs) {
    $vol = Get-Volume -FileSystemLabel $pair.Label -ErrorAction SilentlyContinue
    if (-not $vol) { Write-Warning "No volume with label '$($pair.Label)'"; continue }

    New-Item -ItemType Directory -Path $pair.Path -Force | Out-Null
    $part = Get-Partition | Where-Object { $_.AccessPaths -contains $vol.Path }
    Add-PartitionAccessPath -DiskNumber $part.DiskNumber `
                            -PartitionNumber $part.PartitionNumber `
                            -AccessPath $pair.Path
    Write-Host "Mounted $($pair.Label) at $($pair.Path)"
}

Output:

code

Mounted Archive at C:\Mounts\Archive
Mounted Media at C:\Mounts\Media
Mounted Scratch at C:\Mounts\Scratch

Audit script — every mount and its host

Walk the live mount map across a fleet and roll up CSV.

powershell

$report = foreach ($host in (Get-Content C:\Ops\hostlist.txt)) {
    Invoke-Command -ComputerName $host -ErrorAction SilentlyContinue -ScriptBlock {
        Get-Partition | Where-Object AccessPaths | ForEach-Object {
            foreach ($ap in $_.AccessPaths) {
                [PSCustomObject]@{
                    Host        = $env:COMPUTERNAME
                    DiskNum     = $_.DiskNumber
                    Partition   = $_.PartitionNumber
                    SizeGB      = [math]::Round($_.Size / 1GB, 1)
                    AccessPath  = $ap
                }
            }
        }
    }
}
$report | Sort-Object Host, DiskNum | Format-Table -AutoSize
$report | Export-Csv C:\Ops\mountvol_audit.csv -NoTypeInformation

Output:

sql

Host    DiskNum Partition SizeGB AccessPath
----    ------- --------- ------ ----------
MYHOST        0         2  475.0 C:\
MYHOST        1         1 1862.4 D:\
MYHOST        1         1 1862.4 C:\Mounts\Archive\
SRV01         0         2  237.0 C:\
SRV01         1         1  931.5 C:\Mounts\Backup\

One-shot ESP inspection from WinRE

When troubleshooting an unbootable system from the Windows Recovery Environment, this is the canonical mount-and-look-around recipe.

cmd

diskpart /s mount_esp.txt
mountvol S: /S 2>NUL
dir S:\EFI /S
bcdedit /store S:\EFI\Microsoft\Boot\BCD /enum
mountvol S: /D

Output: (combined — see the directory listing and BCD store dump below)

Where mount_esp.txt contains:

bash

list disk
select disk 0
list partition
exit

Output:

sql

 Directory of S:\EFI\Microsoft\Boot
01/01/2026  09:15            27,648 BCD
01/01/2026  09:15            65,536 BCD.LOG
...
Windows Boot Manager
--------------------
identifier              {bootmgr}
device                  partition=\Device\HarddiskVolume1
description             Windows Boot Manager
default                 {current}
displayorder            {current}
timeout                 30