The Local Security Authority Subsystem Service (LSASS) is a critical Windows process responsible for user authentication and security policies. When lsass.exe consumes excessive CPU resources, it can significantly impact system performance. Let’s explore effective methods to diagnose and fix this issue.
Verify the Authenticity of LSASS.EXE
Before attempting any fixes, it’s crucial to ensure you’re dealing with the legitimate lsass.exe process and not malware masquerading as the system file.
Step 1: Press Ctrl + Shift + Esc to open Task Manager.
Step 2: Locate “Local Security Authority Process” under the Windows processes section.
Step 3: Right-click on the process and select “Open file location”.
Step 4: Verify that the file path is C:\Windows\System32\lsass.exe. If it’s located elsewhere or has a slightly different name (e.g., 1sass.exe), it’s likely malware.
If you suspect malware, run a full system scan with your antivirus software immediately. For additional protection, consider using reputable anti-malware tools like Malwarebytes or Windows Defender offline scan.
Update Windows and Drivers
Outdated system files or drivers can sometimes cause LSASS to behave erratically. Keeping your system up-to-date is a crucial first step in resolving high CPU usage issues.
Step 1: Open the Settings app by pressing Windows + I.
Step 2: Navigate to “Windows Update” and click “Check for updates”.
Step 3: Install all available updates, including optional ones.
Step 4: Restart your computer to apply the changes.
After updating Windows, use a tool like Driver Booster or Windows’ built-in driver update feature to ensure all your device drivers are current.
Run System File Checker (SFC) and DISM
Corrupted system files can cause various issues, including high CPU usage by system processes. The System File Checker (SFC) and Deployment Image Servicing and Management (DISM) tools can help repair these files.
Step 1: Open Command Prompt as administrator by right-clicking the Start button and selecting “Windows Terminal (Admin)”.
Step 2: Run the following command:
sfc /scannow
Step 3: Wait for the process to complete. If SFC finds and repairs issues, restart your computer.
Step 4: If problems persist, run the following DISM commands in order:
DISM /Online /Cleanup-Image /CheckHealth
DISM /Online /Cleanup-Image /ScanHealth
DISM /Online /Cleanup-Image /RestoreHealth
Step 5: Restart your computer after DISM completes its operations.
Check for Problematic Applications
Certain applications, especially those that interact with Windows security features, can cause LSASS to use more CPU resources than normal.
Step 1: Open Task Manager and go to the “Startup” tab.
Step 2: Disable all non-essential startup programs.
Step 3: Restart your computer and monitor LSASS CPU usage.
Step 4: If the issue is resolved, re-enable startup items one by one to identify the problematic application.
Pay special attention to antivirus software, VPN clients, and system optimization tools, as these often interact closely with Windows security features.
Adjust Visual Effects
Windows’ visual effects can sometimes contribute to high CPU usage. Adjusting these settings might help reduce the load on LSASS.
Step 1: Right-click on “This PC” or “My Computer” and select “Properties”.
Step 2: Click on “Advanced system settings”.
Step 3: In the “Performance” section, click “Settings”.
Step 4: Select “Adjust for best performance” or manually uncheck visual effects options.
Step 5: Click “Apply” and “OK”, then restart your computer.
Perform a Clean Boot
A clean boot starts Windows with a minimal set of drivers and startup programs, which can help identify if a third-party application is causing LSASS to use high CPU.
Step 1: Press Windows + R, type msconfig, and press Enter.
Step 2: In the System Configuration window, go to the “Services” tab.
Step 3: Check “Hide all Microsoft services” and click “Disable all”.
Step 4: Go to the “Startup” tab and click “Open Task Manager”.
Step 5: Disable all startup items in Task Manager.
Step 6: Close Task Manager, click “OK” in System Configuration, and restart your computer.
If the issue is resolved in clean boot state, re-enable services and startup items gradually to identify the culprit.
Reset Windows Security
If the issue persists, resetting Windows Security settings might help resolve LSASS high CPU usage.
Step 1: Open Windows Security by searching for it in the Start menu.
Step 2: Go to “App & browser control” > “Reputation-based protection settings”.
Step 3: Turn off all options under “Reputation-based protection”.
Step 4: Restart your computer.
Step 5: Turn the options back on one by one, restarting after each, to identify if a specific setting is causing the issue.
Remember to re-enable these security features after troubleshooting, as they are important for system protection.
Resolving high CPU usage by LSASS can be a complex process, often requiring a combination of these methods. If you’ve tried all these steps and still experience issues, consider creating a new Windows user profile or, as a last resort, performing a clean Windows installation. Always ensure you have backups of your important data before making significant system changes.