(SYStem file) A file extension commonly used for DOS/Windows drivers, such as ANSI.SYS, HIMEM.SYS and KEYBOARD.SYS. See system file. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other ...

The classpnp.sys file is an essential system file ... Click on the Search bar, type Device Manager and open it. Right-click on every piece of hardware, and select Update Driver.

The wdf01000.sys system file belongs to Windows Driver Frameworks ... Click on the Search bar, type Device Manager and open it. Right-click on each device and choose Update Driver.