To perform a successful Multikey 181 x64 install, you need to tell Windows to accept the driver.
The Multikey 181 x64 driver is not Microsoft-signed. To load it, you must either:
bcdedit /set testsigning on
bcdedit /set nointegritychecks on
Description: This feature allows the MultiKey emulator driver to be installed on modern 64-bit Windows systems by temporarily disabling Driver Signature Enforcement and enabling Test Mode. Without this, the installation will fail with an error (e.g., "The hash for the file is not present in the specified catalog").
How to Enable/Use This Feature:
To install MultiKey 181 (or similar versions) on x64 Windows, you must follow this specific procedure to bypass the security checks:
Newer versions (like 19 or 20) exist, but 181 remains the "gold standard" for stability when dealing with legacy CAD software (AutoCAD, ArchiCAD), medical imaging tools, and older ERP systems. It has a proven memory footprint and does not conflict with as many antivirus heuristics.
Even with perfect steps, errors occur. Here is the definitive fix list. multikey 181 x64 install
| Error Code / Symptom | Root Cause | Solution |
| :--- | :--- | :--- |
| Error 1275 (This driver has been blocked from loading) | Driver signature enforcement active | Reboot → Disable driver signing via bcdedit /set nointegritychecks on |
| Code 10 (Device cannot start) | Conflicting driver (e.g., HASP HL driver) | Uninstall original dongle drivers from Device Manager. Reinstall Multikey. |
| BSOD (IRQL_NOT_LESS_OR_EQUAL) | Outdated or corrupted .sys file | Delete multikey.sys from C:\Windows\System32\drivers. Re-extract from archive. |
| Multikey disappears after reboot | Windows Update overwrote settings | Disable automatic driver updates (Group Policy: Computer Config > Admin Templates > Windows Components > Windows Update). |
| Antivirus quarantines multikey.sys | Heuristic detection (hacktool) | Add C:\Multikey181 and C:\Windows\System32\drivers\multikey.sys to antivirus exclusions before install. |
Conflicting versions (e.g., 17xx, 18xx, 20xx) can cause BSODs. Use Device Manager → "Show hidden devices" → Uninstall any "Multikey" or "HASP" entries.
Installing Multikey 181 x64 opens a significant attack surface: To perform a successful Multikey 181 x64 install
Mitigation: Use a dedicated offline machine or a virtual machine with no network access.
If the installation still fails, you may need to force-disable the enforcement via the Advanced Startup options: