Perform a Security Check on Your Computer in Windows
Your Windows computer stores your personal files, passwords, photos, financial information, and important work documents. Because of this, keeping your computer secure should be one of your top priorities.
Even if your PC seems to be working normally, hidden malware, outdated security settings, or vulnerable software can put your data at risk.
The good news is that Windows includes several built-in security features that make it easy to check your computer’s health. By performing a complete security check regularly, you can detect viruses, remove malicious software, identify weak security settings, and ensure your system remains protected from modern cyber threats.
This guide walks you through every important security check in Windows.
Let’s learn in detail!
Types of Security on Your Windows Device
Before performing a security check, it helps to understand the different layers of protection available in Windows.
Virus and Threat Protection
This feature scans your computer for viruses, malware, spyware, ransomware, and other harmful software. Microsoft Defender Antivirus performs automatic scans and provides real-time protection.
Firewall Protection
The Microsoft Defender Firewall monitors incoming and outgoing network traffic. It blocks unauthorized connections that could allow hackers or malicious software to access your computer.
Account Protection
Windows protects your user account using passwords, PINs, Windows Hello, and security recommendations. This helps prevent unauthorized access to your PC.
Device Security
Modern Windows computers include hardware-based security features such as Secure Boot, TPM, and Core Isolation. These technologies help defend your system against advanced attacks.
App and Browser Control
Windows checks downloaded files, websites, and applications before allowing them to run. This helps block dangerous downloads and phishing websites.
Windows Update Security
Keeping Windows updated ensures your computer receives the latest security patches that fix newly discovered vulnerabilities.
Ransomware Protection
Windows includes Controlled Folder Access, which prevents unauthorized applications from changing important files stored in protected folders.
Perform a Security Check on Your Computer in Windows [Complete Guide]
A complete security check involves much more than running a virus scan. Follow these steps carefully to make sure every major area of your Windows computer is protected.
Step 1: Open Windows Security
The first step is to access the built-in security dashboard.
Click the Start button and type Windows Security into the search box. Open the application from the search results. You can also open Settings, select Privacy & Security in Windows 11 or Update & Security in Windows 10, and then choose Windows Security.
The Windows Security dashboard displays the current status of your computer. Green check marks usually indicate that everything is working properly. If you see yellow or red warnings, Windows has detected an issue that needs your attention.
Spend a few moments reviewing each section so you become familiar with your computer’s security status.
Step 2: Check Virus and Threat Protection
Select Virus & Threat Protection from the left panel.
This section shows whether Microsoft Defender Antivirus is running correctly. It also displays your most recent scan, current protection status, and any detected threats.
If Windows reports that antivirus protection is disabled, turn it back on immediately unless another trusted antivirus program is already installed.
Keeping this feature active ensures your computer continuously checks files, downloads, and programs for malicious activity.
Step 3: Run a Quick Scan
A Quick Scan examines the areas where malware is most likely to hide.
Inside Virus & Threat Protection, click Quick Scan.
The scan usually finishes within several minutes, depending on your computer’s speed. During the scan, Windows checks running programs, system files, startup items, and common malware locations.
If no threats are found, Windows will display a confirmation message. If suspicious files are detected, Windows provides options to quarantine or remove them.
Running a Quick Scan at least once each week helps identify problems before they become serious.
Step 4: Perform a Full Scan
A Full Scan is much more thorough than a Quick Scan.
Open Scan Options and choose Full Scan, then click Scan Now.
Unlike the Quick Scan, a Full Scan checks every accessible file, folder, installed program, and connected drive. Because it examines your entire computer, the scan may take one hour or longer.
During this process, avoid shutting down your PC. You may continue using your computer, although performance could be slightly slower until the scan finishes.
If your computer has not been scanned recently, performing a Full Scan is highly recommended.
Step 5: Run Microsoft Defender Offline Scan
Some malware hides before Windows fully starts, making it difficult to remove during a normal scan.
Under Scan Options, choose Microsoft Defender Offline Scan.
Save any open work because Windows will automatically restart your computer. Before Windows loads normally, Defender scans your system for deeply hidden malware.
Once the scan finishes, your computer restarts automatically and displays the scan results after you sign in again.
This scan is especially useful if your antivirus repeatedly detects the same threat or your PC behaves suspiciously.
Step 6: Verify Firewall Protection
Return to the Windows Security home page and open Firewall & Network Protection.
You should see your current network connection marked as active.
Ensure that Microsoft Defender Firewall is turned on. The firewall blocks unauthorized access attempts from the internet and helps prevent attackers from reaching your computer.
Avoid disabling the firewall unless you are troubleshooting a specific network issue and understand the risks involved.
Step 7: Review Device Security
Open Device Security.
This section displays important hardware-based protections, including Secure Boot, Trusted Platform Module (TPM), and Core Isolation if supported by your computer.
These technologies help defend Windows from advanced malware that attempts to attack your computer before the operating system fully loads.
If Windows recommends enabling any available security feature, follow the provided instructions whenever your hardware supports it.
Step 8: Check App and Browser Control
Return to the main Windows Security window and select App & Browser Control.
This area protects you from dangerous websites, harmful downloads, and untrusted applications.
Verify that Smart App Control, Reputation-Based Protection, and Microsoft Defender SmartScreen are enabled where available.
These features warn you before opening potentially unsafe files downloaded from the internet.
Step 9: Confirm Windows Updates Are Installed
Open Settings, then select Windows Update.
Click Check for Updates.
Microsoft frequently releases security updates that fix newly discovered vulnerabilities. Installing these updates keeps your operating system protected against emerging threats.
If updates are available, allow them to download and install completely before restarting your computer.
Keeping Windows updated is one of the easiest ways to improve security.
Step 10: Check Installed Applications
Open Settings and then Apps.
Carefully review your installed programs.
If you notice software that you do not recognize or remember installing, research it before removing it. Unknown applications sometimes arrive with free software downloads and may introduce security risks.
Uninstall only applications you are certain are unnecessary or potentially harmful.
Step 11: Review Startup Programs
Press Ctrl + Shift + Esc to open Task Manager.
Select the Startup Apps tab.
Programs that automatically start with Windows increase startup time and could indicate unwanted software.
Disable applications that you do not need launching automatically, especially those from unknown publishers.
This also improves system performance while reducing opportunities for malicious software to run unnoticed.
Step 12: Check Protection History
Return to Virus & Threat Protection and open Protection History.
This page lists previous detections, quarantined files, blocked threats, and actions performed by Microsoft Defender.
Reviewing this history helps you understand whether Windows has recently detected suspicious activity.
If the same threat appears repeatedly, additional investigation may be necessary because the malware may still be attempting to reinstall itself.
Step 13: Verify Account Security
Open Windows Security and select Account Protection.
Check whether Windows recommends improving your sign-in security.
Using a strong password, Windows Hello PIN, fingerprint recognition, or facial recognition provides better protection against unauthorized access.
If you use a Microsoft account, enable Two-Factor Authentication for additional security.
Step 14: Enable Ransomware Protection
Open Virus & Threat Protection, then select Manage Ransomware Protection.
Turn on Controlled Folder Access if it is available.
This feature prevents unauthorized applications from modifying important folders containing documents, photos, and other valuable files.
Although some legitimate applications may require permission, this feature provides an additional layer of defense against ransomware attacks.
Step 15: Restart Your Computer
After completing every security check, restart your computer.
Restarting allows Windows to finish installing updates, activate security changes, and complete background maintenance tasks.
Once your computer starts again, reopen Windows Security to verify that every protection category displays a green check mark.
How to Fix if You Find Any Viruses?
If Windows detects a virus, remain calm. Microsoft Defender is designed to isolate harmful files before they can spread.
Begin by selecting Quarantine or Remove when Windows presents these options. Quarantined files are isolated so they cannot infect your computer.
Next, perform a Full Scan followed by a Microsoft Defender Offline Scan to ensure no hidden malware remains.
Update Windows completely and install the latest security definitions for Microsoft Defender before scanning again.
Remove any recently installed software that you do not trust or that appeared shortly before the infection.
Change passwords for important accounts such as your email, banking, shopping, and social media accounts if you believe malware may have stolen your credentials.
If your computer continues showing unusual behavior after repeated scans, restore Windows using System Restore if available, or reset Windows while keeping your personal files. As a final option, reinstall Windows from official installation media if the infection cannot be removed.
FAQs
How often should I perform a security check?
A Quick Scan should be performed at least once every week. A Full Scan is recommended once each month or whenever you notice suspicious activity.
Is Microsoft Defender good enough?
Yes. Microsoft Defender Antivirus provides strong protection for most home users when combined with regular Windows updates and safe browsing habits.
Can I use another antivirus program?
Yes. Windows supports many third-party antivirus programs. When one is installed, Microsoft Defender usually adjusts automatically to avoid conflicts.
Does Windows Security slow down my computer?
Security scans use some system resources while running, but modern computers generally handle them with minimal impact. Background protection is optimized to reduce performance loss.
What are signs that my computer may be infected?
Common warning signs include unusually slow performance, unexpected pop-ups, unknown programs, browser redirects, frequent crashes, disabled security features, and files that suddenly become inaccessible.
Should I keep Windows Update enabled?
Yes. Security updates protect your computer from newly discovered vulnerabilities and should always be installed as soon as possible.
Can malware steal my personal information?
Yes. Some malware is designed to steal passwords, banking information, personal files, and other sensitive data. Performing regular security checks significantly reduces this risk.
Summary
Performing a complete security check on your Windows computer is one of the most effective ways to protect your personal information and keep your system running smoothly.
By checking Windows Security, running Quick Scans, performing Full Scans, verifying Firewall Protection, reviewing Device Security, installing Windows Updates, and enabling Ransomware Protection, you create multiple layers of defense against modern cyber threats.
Making these security checks part of your regular maintenance routine helps detect problems early, improves overall system performance, and ensures your Windows computer remains secure for everyday use.