These Nvidia drivers are compatible with Win 10 64-bit and the Quadro K4200:
http://www.nvidia.com/download/driverResults.aspx/116706/en-us
Supported Quadro Series:
Quadro GP100, Quadro P6000, Quadro P5000, Quadro P4000, Quadro P2000, Quadro P1000, Quadro P600, Quadro P400, Quadro M6000 24GB, Quadro M6000, Quadro M5000, Quadro M4000, Quadro M2000, Quadro K6000, Quadro K5200, Quadro K5000, Quadro K4000, Quadro K4200, Quadro K2200, Quadro K2000, Quadro K2000D, Quadro K1200, Quadro K620, Quadro K600, Quadro K420, Quadro 6000, Quadro 5000, Quadro 4000, Quadro 2000, Quadro 2000D, Quadro 600, Quadro 410