Win 11 security won't let me add a Virtual drive letter in File Explorer.


G

GerryPeters

Well-known member
Member
Local time
5:53 PM
Posts
195
OS
WIN 11 PRO
I have a Macrium Reflect image and if I double click it it will let me view the contents of the image in a Virtual drive letter in File Explorer. Win 10 allows this but Win 11 has security that prevents this. How can I fix this?

Google AI had me put this in Command prompt administrator and reboot, but there's more security hurdles to jump through

reg add "HKLM\SYSTEM\CurrentControlSet\Control\CI\Config" /v "VulnerableDriverBlocklistEnable" /t REG_DWORD /d 0 /f
 

My Computers My Computers

System One System Two

  • At a glance

    WIN 11 PROIntel(R) Core(TM) i5-14400 2.50 Ghz,32 Gigs
    OS
    WIN 11 PRO
    Computer type
    PC/Desktop
    Manufacturer/Model
    Custom built - WIN 11 PRO 64-bit ,
    CPU
    Intel(R) Core(TM) i5-14400 2.50 Ghz,
    Motherboard
    ACER Z790 motherboard
    Memory
    32 Gigs
    Hard Drives
    256 gig M2 SSD boot HD, 3 internal HD's, 2 USB

  • At a glance

    Win 10 PROHaswell CPU 4790k @ 4.4GHz,16 Gigs
    Operating System
    Win 10 PRO
    Computer type
    PC/Desktop
    Manufacturer/Model
    CUSTOM
    CPU
    Haswell CPU 4790k @ 4.4GHz,
    Motherboard
    AsRock Z97 motherboard,
    Memory
    16 Gigs
    Hard Drives
    OS drive 250GB SSD,
Hi, is what you're reporting actually this?
Windows 11 updates (such as KB5083769) block the psmounterex.sys driver used by Macrium Reflect 8 to mount backup images as virtual drives. Your actual backup files are safe and can still be restored via rescue media, Windows Update Breaks Macrium Reflect Free. [1, 2, 3]

Why This Happens
  • Blocked Driver: Microsoft added the psmounterex.sys driver to its Vulnerable Driver Blocklist in recent security updates.
  • Affected Versions: This primarily impacts Macrium Reflect 8.1 and the older free version. Newer versions like Macrium Reflect X do not use this blocked driver.
Click to expand...

If so this was extensively discussed months ago when it was first noticed.

If you're using a more recent build of MR, please say which, and post the error message. Thanks.
 

My Computer My Computer

At a glance

Windows 11 Proi7-8650U16GBIntel UHD 620
OS
Windows 11 Pro
Computer type
Laptop
Manufacturer/Model
Lenovo t480s
CPU
i7-8650U
Memory
16GB
Graphics Card(s)
Intel UHD 620
Screen Resolution
1920x1080
Hard Drives
C SN810 SDCPNRY-512G-1006
Browser
Edge, Firefox
Antivirus
Defender
I'm using Macrium 8.0 free. I don't get an error message it just doesn't do anything, yet Win 10 at least opens the F drive but won't let me view the User folder
 

My Computers My Computers

System One System Two

  • At a glance

    WIN 11 PROIntel(R) Core(TM) i5-14400 2.50 Ghz,32 Gigs
    OS
    WIN 11 PRO
    Computer type
    PC/Desktop
    Manufacturer/Model
    Custom built - WIN 11 PRO 64-bit ,
    CPU
    Intel(R) Core(TM) i5-14400 2.50 Ghz,
    Motherboard
    ACER Z790 motherboard
    Memory
    32 Gigs
    Hard Drives
    256 gig M2 SSD boot HD, 3 internal HD's, 2 USB

  • At a glance

    Win 10 PROHaswell CPU 4790k @ 4.4GHz,16 Gigs
    Operating System
    Win 10 PRO
    Computer type
    PC/Desktop
    Manufacturer/Model
    CUSTOM
    CPU
    Haswell CPU 4790k @ 4.4GHz,
    Motherboard
    AsRock Z97 motherboard,
    Memory
    16 Gigs
    Hard Drives
    OS drive 250GB SSD,
GerryPeters said:
I'm using Macrium 8.0 free. I don't get an error message it just doesn't do anything, yet Win 10 at least opens the F drive but won't let me view the User folder
Click to expand...
Not seeing that problem here on Windows 11 and Macrium X. The Users folder is protected by Windows but can be opened if you use an Admin account.
 

My Computer My Computer

At a glance

Windows 11 Pro 25H2 (RP channel)AMD Ryzen 7 9800X3D 8-core64GB Corsair Titanium 6000/CL30MSI Suprim 5080 SOC
OS
Windows 11 Pro 25H2 (RP channel)
Computer type
PC/Desktop
Manufacturer/Model
MSI
CPU
AMD Ryzen 7 9800X3D 8-core
Motherboard
MEG X870E Godlike
Memory
64GB Corsair Titanium 6000/CL30
Graphics Card(s)
MSI Suprim 5080 SOC
Sound Card
Soundblaster AE-9
Monitor(s) Displays
ASUS TUF Gaming VG289Q
Screen Resolution
3840x2160
Hard Drives
Samsung 9100 Pro 4TB (gen 5 x4, system drive/games)
Samsung 990 Pro 2TB
Samsung 980 Pro 2TB
Samsung 870 Evo 4TB
Samsung 870 Evo 2TB
Samsung T9 4TB
PSU
Seasonic PX-2200
Case
Bequiet! Dark Base Pro 901
Cooling
Noctua NH-D15S Chromax black
Keyboard
Logitech G915 X (wired)
Mouse
Logitech G903 with PowerPlay charger
Internet Speed
900Mb/sec
Browser
Microsoft Edge
Antivirus
Windows Defender
GerryPeters said:
I'm using Macrium 8.0 free. I don't get an error message it just doesn't do anything, yet Win 10 at least opens the F drive but won't let me view the User folder
Click to expand...
Thank you for your reply.

I have already explained what you're seeing. If you had followed my hint and read about it elsewhere on Windows 11 you wouldn't be posting back with the same problem.

Why?

Mounting an image on Win 11 with older versions of Macrium Reflect no longer works.

Macrium Reflect X (current version) does that a different way and does not use the driver Win 11 (MS) blocks.

Workarounds (of a kind) were posted in discussions on this months ago. That includes using MR's boot disk.
 

My Computer My Computer

At a glance

Windows 11 Proi7-8650U16GBIntel UHD 620
OS
Windows 11 Pro
Computer type
Laptop
Manufacturer/Model
Lenovo t480s
CPU
i7-8650U
Memory
16GB
Graphics Card(s)
Intel UHD 620
Screen Resolution
1920x1080
Hard Drives
C SN810 SDCPNRY-512G-1006
Browser
Edge, Firefox
Antivirus
Defender

My Computers My Computers

System One System Two Other systems

  • At a glance

    Windows 11 Pro 26H2 26300.9457i9-10900 10 core 20 threads32 gbnone-Intel UHD Graphics 630
    OS
    Windows 11 Pro 26H2 26300.9457
    Computer type
    PC/Desktop
    Manufacturer/Model
    Dell Optiplex 7080
    CPU
    i9-10900 10 core 20 threads
    Motherboard
    DELL 0J37VM
    Memory
    32 gb
    Graphics Card(s)
    none-Intel UHD Graphics 630
    Sound Card
    Integrated Realtek
    Monitor(s) Displays
    Benq 27
    Screen Resolution
    2560x1440
    Hard Drives
    2x1tb Solidigm m.2 nvme /External drives 512gb Samsung m.2 sata+2tb Kingston m2.nvme
    PSU
    500w
    Case
    MT
    Cooling
    Dell Premium
    Keyboard
    Logitech wired
    Mouse
    Logitech wireless
    Internet Speed
    so slow I'm too embarrassed to tell
    Browser
    #1 Edge #2 Firefox
    Antivirus
    Defender+MWB Premium

  • At a glance

    Windows 11 Pro 24H2 26200.9457AMD Ryzen 7 6800U32 gbintegrated
    Operating System
    Windows 11 Pro 24H2 26200.9457
    Computer type
    PC/Desktop
    Manufacturer/Model
    Beelink Mini PC SER5
    CPU
    AMD Ryzen 7 6800U
    Memory
    32 gb
    Graphics card(s)
    integrated
    Sound Card
    integrated
    Monitor(s) Displays
    Benq 27
    Screen Resolution
    2560x1440
    Hard Drives
    1TB Crucial nvme
    Keyboard
    Logitech wired
    Mouse
    Logitech wireless
    Internet Speed
    still too embarrassed to tell
    Browser
    Firefox
    Antivirus
    Defender
  • System 3 is non compliant Dell 9020 i7-4770/24gb ram Win11 PRO 26200.9457
The registry fix doesn't work anymore. It's extremely rare that I need to look at the contents of an image file. I think I can view it if I use the Macrium boot CD. Is that correct? Macrium free works fine, no need to upgrade to the paid Macrium X for me
 

My Computers My Computers

System One System Two

  • At a glance

    WIN 11 PROIntel(R) Core(TM) i5-14400 2.50 Ghz,32 Gigs
    OS
    WIN 11 PRO
    Computer type
    PC/Desktop
    Manufacturer/Model
    Custom built - WIN 11 PRO 64-bit ,
    CPU
    Intel(R) Core(TM) i5-14400 2.50 Ghz,
    Motherboard
    ACER Z790 motherboard
    Memory
    32 Gigs
    Hard Drives
    256 gig M2 SSD boot HD, 3 internal HD's, 2 USB

  • At a glance

    Win 10 PROHaswell CPU 4790k @ 4.4GHz,16 Gigs
    Operating System
    Win 10 PRO
    Computer type
    PC/Desktop
    Manufacturer/Model
    CUSTOM
    CPU
    Haswell CPU 4790k @ 4.4GHz,
    Motherboard
    AsRock Z97 motherboard,
    Memory
    16 Gigs
    Hard Drives
    OS drive 250GB SSD,
GerryPeters said:
I'm using Macrium 8.0 free. I don't get an error message it just doesn't do anything, yet Win 10 at least opens the F drive but won't let me view the User folder
Click to expand...
Ah, you have successfully unblocked the psmounterex.sys that Reflect v8 uses to mount images.
But you missed a trick when mounting the drive letter. You just need to tick the box for 'Enable access to restricted folders'.

1649322655953-png.26364
 

My Computers My Computers

System One System Two Other systems

  • At a glance

    Windows 11 HomeAMD Athlon Silver 3050U8GBRadeon Graphics
    OS
    Windows 11 Home
    Computer type
    Laptop
    Manufacturer/Model
    Acer Aspire 3 A315-23-R9VY
    CPU
    AMD Athlon Silver 3050U
    Memory
    8GB
    Graphics Card(s)
    Radeon Graphics
    Monitor(s) Displays
    laptop screen
    Screen Resolution
    1366x768 native resolution, up to 2560x1440 with Radeon Virtual Super Resolution
    Hard Drives
    1TB Samsung EVO 870 SSD (from April 2026: 250GB EVO 850)
    Internet Speed
    150 Mbps
    Browser
    Edge, Firefox
    Antivirus
    Defender
    Other Info
    UPDATE - 11 April 2026: due to lid hinges starting to break up this laptop has been retired from active duty. The OS with all software and files has been migrated to my System Seven in 'Other systems' to carry on as my general purpose 'main machine'.

    I've now clean installed 25H2 and used Garlin's scripts to update Secure Boot to CA 2023 and revoke the PCA 2011 certificates. It's new role is to test secure boot issues.

    Info for 2021-2026:
    fully 'Windows 11 ready' laptop. Windows 10 C: partition migrated from my old unsupported 'main machine' then upgraded to 11. A test migration ran Insider builds for 2 months. When 11 was released on 5th October 2021 it was re-imaged back to 10 and was offered the upgrade in Windows Update on 20th October. Windows Update offered the 22H2 Feature Update on 20th September 2022. It got the 23H2 Feature Update on 4th November 2023 through Windows Update, 24H2 on 3rd October 2024 through Windows Update by setting the Target Release Version for 24H2, and 25H2 on 30th September 2025 through Windows Update by setting the Target Release Version for 25H2.

  • At a glance

    Windows 11 ProIntel® Core™ i5-520M8GB(integrated graphics) Intel HD Graphics
    Operating System
    Windows 11 Pro
    Computer type
    Laptop
    Manufacturer/Model
    Dell Latitude E4310
    CPU
    Intel® Core™ i5-520M
    Motherboard
    0T6M8G
    Memory
    8GB
    Graphics card(s)
    (integrated graphics) Intel HD Graphics
    Screen Resolution
    1366x768
    Hard Drives
    500GB Crucial MX500 SSD
    Browser
    Firefox, Edge
    Antivirus
    Defender
    Other Info
    unsupported machine: Legacy bios, MBR, TPM 1.2, upgraded from W10 to W11 using W10/W11 hybrid install media workaround.

    In-place upgrade to 22H2 using ISO and a workaround.
    Feature Update to 23H2 by manually installing the Enablement Package.
    In-place upgrade to 24H2 using hybrid 23H2/24H2 install media.
    Upgraded to 25H2 by Enablement Package.
    Upgraded to 26H2 by Enablement Package.

    Also running Insider Experimental 263xx and 29xxx builds and Windows 10 as native boot .vhdx.
  • My SYSTEM THREE is a Dell Latitude 5410, i7-10610U, 32GB RAM, 512GB NVMe ssd, supported device running Windows 11 Pro.

    My SYSTEM FOUR was a 2-in-1 convertible Lenovo Yoga 11e (1st gen) type 20DA, Celeron N2930, 8GB RAM, 256GB ssd. Unsupported device. This has now been sold. It has been replaced by my System Eight.

    My SYSTEM FIVE is a Dell Latitude 3190 2-in-1, Pentium Silver N5030, 8GB RAM, 1TB NVMe ssd, supported device running Windows 11 Pro, plus Insider Beta, Experimental 263xx and 29xxx builds (and a few others) as a native boot .vhdx.

    My SYSTEM SIX is a Dell Latitude 5550, Core Ultra 7 165H, 64GB RAM, 1TB NVMe SSD, supported device, Windows 11 Pro, Hyper-V host machine. Updated to 25H2 on 30th September 2025.

    My SYSTEM SEVEN is a Lenovo Thinkpad T580, 1920x1080 touchscreen, Intel Core i7-8650U, 16GB RAM, 512GB NVMe SSD + 2nd 512GB NVMe SSD, a supported device for Windows 11. This is my current general purpose 'main machine'. The installed Windows 11 Home from my System One has been migrated to this machine. As its new home has an existing digital licence for Pro I've been able to upgrade the migrated OS from Home to Pro.
    29 Sept. 2026 Feature Update to 26H2 through Windows Update.

    My SYSTEM EIGHT is a 2-in-1 convertible Lenovo Yoga 11e (5th gen) type 20LN, Celeron N4120, 8GB RAM, 512GB NVMe ssd, a supported device for Windows 11. Currently running Windows 11 Pro, plus Insider Beta, Experimental 263xx and 29xxx builds as native boot vhdx.
Enable access to restricted folders - on WIN 11 if I check that box the window does pop up saying assigning drive letter F, but nothing happens. I don't see it in File Explorer This doesn't work on WIN 11 but on Win 10 it does, it allows me to view all folders under Users on the Macrium file that I copied from Win 11 to my Win 10 computer.

I then opened the Macrium file inside the Win 11 mapped network folder from my Win 10 computer with the check box and it worked. So in other words if I ever want to view the flies inside a Macrium file, I can do it from my Win 10 computer without having to copy it to my Win 10 computer. Thanks Bree you're the best!

So I guess the Registry change I did doesn't affect any of this and I can revert back to the normal Registry value. Let me know
 

My Computers My Computers

System One System Two

  • At a glance

    WIN 11 PROIntel(R) Core(TM) i5-14400 2.50 Ghz,32 Gigs
    OS
    WIN 11 PRO
    Computer type
    PC/Desktop
    Manufacturer/Model
    Custom built - WIN 11 PRO 64-bit ,
    CPU
    Intel(R) Core(TM) i5-14400 2.50 Ghz,
    Motherboard
    ACER Z790 motherboard
    Memory
    32 Gigs
    Hard Drives
    256 gig M2 SSD boot HD, 3 internal HD's, 2 USB

  • At a glance

    Win 10 PROHaswell CPU 4790k @ 4.4GHz,16 Gigs
    Operating System
    Win 10 PRO
    Computer type
    PC/Desktop
    Manufacturer/Model
    CUSTOM
    CPU
    Haswell CPU 4790k @ 4.4GHz,
    Motherboard
    AsRock Z97 motherboard,
    Memory
    16 Gigs
    Hard Drives
    OS drive 250GB SSD,
GerryPeters said:
The registry fix doesn't work anymore. It's extremely rare that I need to look at the contents of an image file. I think I can view it if I use the Macrium boot CD. Is that correct?
Click to expand...
Only if you boot from rescue media that was made before MS update the blocked drivers list.
GerryPeters said:
Enable access to restricted folders - on WIN 11 if I check that box the window does pop up saying assigning drive letter F, but nothing happens. I don't see it in File Explorer This doesn't work on WIN 11 but on Win 10 it does, it allows me to view all folders under Users on the Macrium file that I copied from Win 11 to my Win 10 computer.

I then opened the Macrium file inside the Win 11 mapped network folder from my Win 10 computer with the check box and it worked. So in other words if I ever want to view the flies inside a Macrium file, I can do it from my Win 10 computer without having to copy it to my Win 10 computer. Thanks Bree you're the best!

So I guess the Registry change I did doesn't affect any of this and I can revert back to the normal Registry value. Let me know
Click to expand...
I would revert back, you'd want Windows 11 to be protected from vulnerable drivers.

My personal workaround for Win11/Reflect v8 is to use an older winre.wim as a custom WIM for the rescue media builder, then add Reflect to the boot menu. The few times I need to recover a file from an image I can boot to Reflect and use that to mount the image and browse it. See here for more details:

Bree said:
The vulnerable driver block list is baked into Windows, and that includes into the Winre.wim that Reflect uses to build the rescue USB. If you have an older boot USB you can boot from it and explore a mounted image.....

....If you don't have an old USB you can make one. You just need to find a copy of Winre.wim from before psmounterex.sys was blocked, either from an old image or use 7-Zip file manager to extract it from the install.esd (or install.wim) on older install media. Put this in a folder somewhere and set the Reflect Media Builder to use this as a 'custom WIM'.
Click to expand...
Need to find a decent backup, restore and cloning software - post #45
 

My Computers My Computers

System One System Two Other systems

  • At a glance

    Windows 11 HomeAMD Athlon Silver 3050U8GBRadeon Graphics
    OS
    Windows 11 Home
    Computer type
    Laptop
    Manufacturer/Model
    Acer Aspire 3 A315-23-R9VY
    CPU
    AMD Athlon Silver 3050U
    Memory
    8GB
    Graphics Card(s)
    Radeon Graphics
    Monitor(s) Displays
    laptop screen
    Screen Resolution
    1366x768 native resolution, up to 2560x1440 with Radeon Virtual Super Resolution
    Hard Drives
    1TB Samsung EVO 870 SSD (from April 2026: 250GB EVO 850)
    Internet Speed
    150 Mbps
    Browser
    Edge, Firefox
    Antivirus
    Defender
    Other Info
    UPDATE - 11 April 2026: due to lid hinges starting to break up this laptop has been retired from active duty. The OS with all software and files has been migrated to my System Seven in 'Other systems' to carry on as my general purpose 'main machine'.

    I've now clean installed 25H2 and used Garlin's scripts to update Secure Boot to CA 2023 and revoke the PCA 2011 certificates. It's new role is to test secure boot issues.

    Info for 2021-2026:
    fully 'Windows 11 ready' laptop. Windows 10 C: partition migrated from my old unsupported 'main machine' then upgraded to 11. A test migration ran Insider builds for 2 months. When 11 was released on 5th October 2021 it was re-imaged back to 10 and was offered the upgrade in Windows Update on 20th October. Windows Update offered the 22H2 Feature Update on 20th September 2022. It got the 23H2 Feature Update on 4th November 2023 through Windows Update, 24H2 on 3rd October 2024 through Windows Update by setting the Target Release Version for 24H2, and 25H2 on 30th September 2025 through Windows Update by setting the Target Release Version for 25H2.

  • At a glance

    Windows 11 ProIntel® Core™ i5-520M8GB(integrated graphics) Intel HD Graphics
    Operating System
    Windows 11 Pro
    Computer type
    Laptop
    Manufacturer/Model
    Dell Latitude E4310
    CPU
    Intel® Core™ i5-520M
    Motherboard
    0T6M8G
    Memory
    8GB
    Graphics card(s)
    (integrated graphics) Intel HD Graphics
    Screen Resolution
    1366x768
    Hard Drives
    500GB Crucial MX500 SSD
    Browser
    Firefox, Edge
    Antivirus
    Defender
    Other Info
    unsupported machine: Legacy bios, MBR, TPM 1.2, upgraded from W10 to W11 using W10/W11 hybrid install media workaround.

    In-place upgrade to 22H2 using ISO and a workaround.
    Feature Update to 23H2 by manually installing the Enablement Package.
    In-place upgrade to 24H2 using hybrid 23H2/24H2 install media.
    Upgraded to 25H2 by Enablement Package.
    Upgraded to 26H2 by Enablement Package.

    Also running Insider Experimental 263xx and 29xxx builds and Windows 10 as native boot .vhdx.
  • My SYSTEM THREE is a Dell Latitude 5410, i7-10610U, 32GB RAM, 512GB NVMe ssd, supported device running Windows 11 Pro.

    My SYSTEM FOUR was a 2-in-1 convertible Lenovo Yoga 11e (1st gen) type 20DA, Celeron N2930, 8GB RAM, 256GB ssd. Unsupported device. This has now been sold. It has been replaced by my System Eight.

    My SYSTEM FIVE is a Dell Latitude 3190 2-in-1, Pentium Silver N5030, 8GB RAM, 1TB NVMe ssd, supported device running Windows 11 Pro, plus Insider Beta, Experimental 263xx and 29xxx builds (and a few others) as a native boot .vhdx.

    My SYSTEM SIX is a Dell Latitude 5550, Core Ultra 7 165H, 64GB RAM, 1TB NVMe SSD, supported device, Windows 11 Pro, Hyper-V host machine. Updated to 25H2 on 30th September 2025.

    My SYSTEM SEVEN is a Lenovo Thinkpad T580, 1920x1080 touchscreen, Intel Core i7-8650U, 16GB RAM, 512GB NVMe SSD + 2nd 512GB NVMe SSD, a supported device for Windows 11. This is my current general purpose 'main machine'. The installed Windows 11 Home from my System One has been migrated to this machine. As its new home has an existing digital licence for Pro I've been able to upgrade the migrated OS from Home to Pro.
    29 Sept. 2026 Feature Update to 26H2 through Windows Update.

    My SYSTEM EIGHT is a 2-in-1 convertible Lenovo Yoga 11e (5th gen) type 20LN, Celeron N4120, 8GB RAM, 512GB NVMe ssd, a supported device for Windows 11. Currently running Windows 11 Pro, plus Insider Beta, Experimental 263xx and 29xxx builds as native boot vhdx.
You must log in or register to reply here.

Similar threads

Solved Sorting drives by drive letter in file explorer and changing search menu
Replies
11
Views
2K
PBzeer
PBzeer
Win 11 update from 10 won't let me go back even though windows old is visible
Replies
19
Views
5K
zbook
Z
  • Article Article
Devices Change Drive Letter in Windows 11
Replies
0
Views
39K
Brink
Brink

Latest Support Threads

Latest Tutorials

Back
Top Bottom