Windows 10: Occasional BSOD (Kernel Security Check Failure), high CPU usage

Hi community,
usually I don't post in forums, but I'm afraid I'm stuck. Also, I have two issues that I believe are interrelated, so I hope I'm correct in this part of the forum:
1) Occasional BSODs (three since 27 June)
2) extremely high CPU usage that makes using my PC hard

A few days ago, while working on my Lenovo T520 notebook for about two hours already, I got a Kernel Security Check Failure BSOD. After restarting, the PC worked just fine, only Windows Defender showed a faulty driver. I manually updated it (I think it was for the memory card or so) and the PC worked fine for some hours before I got another BSOD (driver verifier detected violation). However, after restart, the driver manager did not show any problems, and manually updating some third party drivers did not help, all were supposedly new. Here is a .dmp from the, as I think, second BSOD: Dropbox - 062818-27953-01.dmp

What I did since then and what other complications occurred:
1) Make sure Windows 10 is up to date
2) Updating BIOS
3) Using third party software to update all drivers automatically (15 drivers updated)
However, after another BSOD (now Kernel Security Check Failure again), my computer is on constant high CPU usage (usually around 75%, often 100%, and it takes ages for programs to start) and I can hardly use it for work. However, there is no single process that is taking up the memory, often e.g. firefox is first with around 40 percent or so, but it seems to sum up in a weird way. (After fresh boot, not opening any programs, after some time the fan stops working and CPU is low. But that only works without opening any programs.) So I randomly did:
4) sfc /scannow (no errors)
5) chkdsk (no errors)
6) windows start up repair (because I was desperate - of course nothing changed)
7) boot in safe mode - the computer runs smooth again!
8) do a clean boot - same problems as before

When doing a clean boot, the services running are exactly the same as in safe mode, and still I have problems in the former but not in safe mode.
a) What can I do to get normal CPU usage?
b) How can I assure the BSOD does not return? I have lost some unsaved files because of this.

:)

 

BSOD - Kernel Security Check Failure

Hi Ashton,

There's a lot of reason for booting in to a BSOD, like problems with the driver for your display adapter or the
video output is being sent to an unexpected port. KERNEL SECURITY CHECK FAILURE error is usually caused by Memory or Driver incompatibility issues or corruption of system data.
In order for us to efficiently assist you, we just have few questions for you:

• Were there any changes made to your computer prior to the issue?
• What troubleshooting steps have you done so far?

Regards.

 

BSOD Kernel security check failure


Attachment 29243

Recieving the BSOD once a day, at least. My drivers are up to date so far as I know and I've tried various methods of troubleshooting including the steps outlined here:

What does the Kernel Security Check Failure Blue Screen error mean?

Hoping you guys may have some insight...

 

BSOD Kernel Security Check Failure