Kernel Security Check Failure is a critical Windows error leading to a BSOD, caused by various factors like memory problems, outdated drivers, viruses, and more.
Steps to fix the error include booting into Safe Mode, using Windows Memory Diagnostic, fixing corrupted Windows files, addressing hard disk errors, updating/uninstalling drivers, scanning for viruses, and resetting the Windows Operating System.
To boot into Safe Mode, restart the PC while holding Shift key or via F8 key during boot; for Windows Memory Diagnostic, press Windows key + R, type mdsched.exe, and restart; for fixing corrupted files, use PowerShell command sfc /scannow.
To fix hard disk errors, use CHKDSK command by right-clicking Windows icon, selecting Command Prompt (Admin), and entering chkdsk /x; updating drivers in Device Manager, scanning with antivirus like Malwarebytes, and resetting Windows OS are also recommended solutions.