By default, Windows 11 will block the installation of unsigned or legacy kernel-mode drivers (which MultiKey usually is). You must disable this enforcement temporarily.
Before committing to the MultiKey driver, consider modern alternatives: virtual usb multikey 64 bit driver windows 11
A virtual USB MultiKey driver intercepts API calls (specifically HID and Smart Card interfaces) from the protected application and redirects them to a software-emulated dongle. The emulator loads a signed 64-bit driver that Windows 11 accepts, creating a virtual USB device. Inside this virtual device, you load a "dump" or "image" of your original physical dongle’s data. By default, Windows 11 will block the installation
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