System32 → 64‑bit files SysWOW64 → 32‑bit files (Windows‑on‑Windows 64)
If your app (e.g., C#, VB.NET) still throws “DllNotFoundException” : zkemkeeper.dll install 64 bit
regsvr32 C:\Windows\System32\zkemkeeper.dll System32 → 64‑bit files SysWOW64 → 32‑bit files