What Is an ATI Radeon Kernel Mode Driver?by Dan Stone
An ATI (now AMD) Radeon Kernel Mode Driver is the program that allows an ATI Radeon video card to directly operate with the computer's operating system and CPU.
If a computer were described like an organism, the kernel would be the brain. It has the highest level of control over everything that happens within the computer. For example, a game that is displaying onscreen graphics operates with the kernel-mode driver, which would operate with the kernel to render the image on the computer screen.
The kernel mode refers to the program being "trusted," which means it does not have any restrictions and can address all of the computer's memory. If the software is not trusted, it is not able to freely access other software and is referred to as "user."
Because a kernel-mode driver can access all of a computer's memory, errors in it can cause the computer to crash. When a program experiences an error, it typically only takes down itself. However, kernel-mode programs can take down any number of other programs with them -- including the operating system -- when they experience errors.