The Ez100pu is a legacy driver for USB-based Smart Card Readers (specifically those compliant with the PC/SC standard, often manufactured by OMNIKEY or Feitian). It is notoriously problematic on Windows 11 due to:
If the device still shows a "Code 31" error or fails to function: Ez100pu Driver Windows 11
However, Windows 11 Pro and Enterprise editions include Smart Card Plug and Play (SCPnP). If your Ez100pu driver is installed correctly, SCPnP will automatically handle the smart card’s minidriver without extra software for basic certificates. Deep Report: Ez100pu Driver on Windows 11 1
Clean the chip: Use a soft cloth to wipe the gold contact on your smart card. If your Ez100pu driver is installed correctly, SCPnP
Select device in Device Manager → Update driver → “Have Disk” → point to .inf.
The "Core Isolation" Fix: If installation fails, try turning off Memory Integrity in the Windows Security app under Device Security > Core Isolation details. 3. Advanced Solutions for Persistence
The Windows 11 Challenge: Windows 11 has stricter driver signing requirements and has deprecated many older kernel-mode drivers. Older versions of the Ez100pu driver (especially pre-2015 versions) will be blocked outright by Windows 11’s security features. This is why a simple “plug and play” usually fails.