Usermode-driver-kit.rar -

: Windows requires drivers to be digitally signed. If the contents of that RAR include .sys or .dll files that aren't signed by a verified publisher, Windows will likely block them or require "Test Mode" to run. How to Proceed Safely

: These drivers have restricted access to system memory and hardware, making them inherently safer for the OS than kernel-mode drivers. usermode-driver-kit.rar

If you found a file named usermode-driver-kit.rar on a forum or a third-party site (rather than an official Microsoft repository), it is likely one of two things: : Windows requires drivers to be digitally signed

: A bundle of C++ headers and libraries pre-configured to help developers start a driver project quickly. usermode-driver-kit.rar