Locate your MultiKey 18.1.0 (x64) folder. It usually contains multikey.sys , multikey.inf , and a registry file ( .reg ). Copy multikey.sys to C:\Windows\System32\drivers . Right-click the Start button and select Device Manager .
: Missing Visual C++ redistributables or corrupted .sys file. Fix : Install all VC++ runtimes (2005-2022) and verify file hash of multikey.sys . multikey 181 x64 install