To resolve the Virtual USB MultiKey Error Code 39 on Windows 11, the most effective solution is disabling Core Isolation (Memory Integrity) , a security feature that often blocks older virtual drivers. The following blog post outlines why this happens and how to fix it using verified methods. How to Fix Virtual USB MultiKey "Error Code 39" on Windows 11 If you use software that relies on a virtual USB dongle or a MultiKey USB Bus Enumerator , you may have encountered a frustrating yellow exclamation mark in your Device Manager accompanied by this message: "Windows cannot load the device driver for this hardware. The driver may be corrupted or missing (Code 39)." This error is incredibly common on Windows 11 because the OS has stricter security protocols than its predecessors. Here is how to get your virtual key back online. Why is this happening? The primary culprit in Windows 11 is Core Isolation (specifically Memory Integrity) . This security layer prevents drivers that do not meet modern security standards from loading into high-security memory areas. Since many MultiKey drivers are older or "virtualized," Windows 11 blocks them by default, resulting in Code 39. Solution 1: Disable Core Isolation (Most Effective) The most direct way to fix this is to tell Windows to allow the driver to run by turning off Memory Integrity. Open Windows Security (search for it in the Start menu). Navigate to Device Security on the left sidebar. Click on Core isolation details . Toggle the Memory integrity switch to Off . Restart your computer . After rebooting, check Device Manager to see if the Code 39 error has disappeared. Solution 2: Registry Fix (If Core Isolation isn't enough) If the error persists, you can force Windows to ignore certain integrity checks through the Windows Registry Editor. Warning: Be careful; editing the registry incorrectly can damage your system. Press Win + R , type regedit , and hit Enter. Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity . Find the Enabled DWORD and double-click it. Change the Value data to 0 and click OK. Restart your PC. Solution 3: Remove Registry Filters Sometimes, "Filters" attached to the USB class in the registry get corrupted, preventing drivers from loading. In the Registry Editor, go to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{36fc9e60-c465-11cf-8056-444553540000} (This is the class ID for USB controllers). Look for values named UpperFilters or LowerFilters in the right pane. If they exist, right-click and Delete them. Restart your system. Solution 4: Clean Reinstall If all else fails, a fresh start for the driver might be necessary. Open Device Manager , right-click your MultiKey device, and select Uninstall device . In the top menu, click Action > Scan for hardware changes . If it doesn't reinstall automatically, manually point Windows to your driver files by selecting Browse my computer for drivers . Pro Tip: Always ensure you are using the latest version of the MultiKey driver. Many manufacturers have released updated versions specifically for Windows 11 that are compatible with Core Isolation. Tell me what specific hardware or software you're trying to run! How to Fix USB Driver Error Code 39 - Matsusada Precision
Virtual USB Multikey Code 39 on Windows 11: Bridaging Legacy Hardware Protection with Modern OSes In the world of software licensing and hardware-based digital rights management (DRM), the Sentinel Hardware Key (often referred to as HASP or SentinelPro) has been a long-standing solution. Among its variants, the Multikey — a software emulator or driver package designed to simulate these physical dongles — occupies a unique, legally gray, yet technically significant niche. The term “Code 39” typically refers to a specific error or device instance identifier in Windows, signaling a driver installation or hardware recognition issue. When combined with Windows 11 , this trio presents both a challenge and a solution for users of legacy industrial, medical, or design software. 1. Understanding the Components
Virtual USB Device : A software-emulated USB device that mimics a physical dongle’s presence, VID/PID (Vendor ID/Product ID), and internal memory. It relies on kernel-mode drivers to intercept system calls from protected applications. Multikey : A well-known driver-level emulator (originally by “HASPEmul” or later versions like MultiKey 18.x, 19.x) that allows running multiple virtual dongles simultaneously. It hooks into Windows’ Plug and Play (PnP) subsystem. Code 39 : In Windows Device Manager, this status code means “Windows cannot load the device driver for this hardware because a previous instance of the driver is still in memory.” It often appears after incomplete uninstalls, driver conflicts, or when trying to force unsigned drivers onto a system with Secure Boot or Memory Integrity enabled. Windows 11 : Microsoft’s latest OS introduces stricter driver signing requirements (WHQL), mandatory Secure Boot by default, Hypervisor-Protected Code Integrity (HVCI), and Kernel DMA Protection — all of which break older kernel-mode emulators.
2. The Core Conflict: Windows 11’s Security vs. Legacy Emulation Multikey drivers (typically .sys files dated from 2005–2012) are unsigned or signed with deprecated SHA-1 certificates. Windows 11, especially on fresh installations, blocks loading such drivers via: Virtual Usb Multikey Code 39 Windows 11
Secure Boot : Prevents unsigned boot-start drivers. Memory Integrity (HVCI) : Blocks any driver that violates virtualization-based security. Driver Signature Enforcement : Requires SHA-2, WHQL-signed drivers for kernel-mode.
As a result, attempting to install a Virtual USB Multikey device leads directly to Code 39 — Windows recognizes the device (thanks to the .inf file), but refuses to start the driver, leaving it in a failed state. 3. Why Do People Still Need This? Legacy automation software (CNC machines, medical analyzers, CAD/CAM from the early 2000s) often relies on physical parallel or USB dongles. When the original dongle fails (e.g., dead EEPROM) or is lost, and the vendor no longer exists, users turn to virtual emulation to keep critical systems running. The “Virtual USB” approach also allows running such software on modern laptops without physical dongles (e.g., for remote diagnostics). 4. Getting It to Work on Windows 11: A Practical Guide (Educational Only) Note: This is for educational purposes regarding system administration of legacy software. Emulating protected dongles may violate software licenses. If you absolutely need to run a Multikey-emulated device on Windows 11, here is the general process (as shared by legacy hardware communities): Step 1 – Disable Integrity Checks (Temporarily)
Restart into Advanced Startup → Disable Driver Signature Enforcement . Or use bcdedit /set testsigning on (places a watermark on desktop). Disable Memory Integrity under Windows Security → Device Security → Core Isolation. To resolve the Virtual USB MultiKey Error Code
Step 2 – Install Multikey Driver in a Compatible Mode
Use DevCon or pnputil to add the driver package. Often requires manually adding hardware via “Add Legacy Hardware” in Device Manager, selecting the Multikey .inf file.
Step 3 – Resolve Code 39 Specifically Code 39 appears when the driver’s DriverEntry routine fails or a previous driver instance is stuck. Solutions include: The driver may be corrupted or missing (Code 39)
Using devcon remove *multikey* then rescan. Editing the registry to delete UpperFilters / LowerFilters under the device’s Enum key. Ensuring no other HASP/Sentinel drivers (e.g., aksfridge.sys ) are running. Replacing the Multikey .sys with a version patched to support larger IRP buffers (common in v18.2.3 for x64).
Step 4 – Virtual USB Abstraction Some advanced setups use a USB over IP redirection or a virtual machine (VM) with USB passthrough: run the dongle emulation inside a Windows 7 VM (where drivers load freely) and redirect the virtual USB device to Windows 11 via network. This bypasses native driver loading entirely. 5. Risks and Realities