I recently ran into a strange issue where a process called NT Kernel & System was using 15 to 30 percent of the CPU on my Windows computer all the time.
In the above screenshot, the system is using 0 percent of the CPU as it should normally be. The system process mainly contains kernel and driver code as well as system threads and is an essential Windows process. Do not try to stop the process or delete it.
Before getting into the technical details, this issue is usually caused by a bad or outdated hardware driver in Windows. There are a few things to check immediately:
New equipment. Have you recently installed any new hardware on your Windows computer? Video card, hard drive, sound card, TV tuner, etc.? If so, you need to go to the manufacturer’s website and download the latest driver from there. If you only installed the driver from the CD that came with the new hardware, it may be out of date.
Updated Driver – Have you recently updated your driver and have noticed higher CPU usage after updating? Sometimes the latest drivers can also cause problems. In this case, you should try rolling back the driver and see if that solves the problem.
In my case, I installed a new graphics card on my computer and installed the driver from the CD. It was not the last driver, and since it was a kernel mode driver it caused a splash in the system process.
If you cannot determine which driver is causing the problem, there is an additional technical procedure that you can follow to find exactly the problematic driver. First download KrView (Kernrate Viewer) which is a free tool from Microsoft.
It is a command line tool, so open a command prompt and then just run the program with no arguments. The results should look like this:
Now you can see which device drivers are getting the most kernel hits. The first is called ntkrnlpa and can be ignored. After that, you want to look at other drivers. In this case, b57nd60x. So, is this driver for which hardware you are interested in?
Well, to figure it out, you need to download another free tool from Microsoft called Process Explorer Install it, run it, and then go to DLL view to see the loaded drivers.
As you can see the DLL b57nd60x.sys is the driver for the Broadcom NetXtreme Gigabit Ethernet card. Sweet! Now you just need to find an updated driver for your network card and hopefully the spike in CPU usage goes away.
Of course, another solution in this case is to simply disable that hardware or completely remove it from the system if you don’t need it or can’t find an updated driver. Source: Technet