MAIN COMPONENTS OF A COMPUTER

 

Malware infections remain one of the most serious threats to Windows systems. Viruses, ransomware, spyware, trojans, and rootkits can damage files, slow performance, steal personal data, or completely disable your PC. Knowing how to troubleshoot and remove malware safely is essential for both home users and IT technicians.

This guide covers safe detection, isolation, removal, and recovery techniques to restore your Windows system to full health.

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🦠 1. Understanding Malware and Its Effects

Common Types of Malware

• Virus: Infects and replicates through other files.
• Trojan: Disguised as legitimate software to gain control.
• Spyware: Monitors and records user activity.
• Adware: Displays unwanted ads and tracks browsing behavior.
• Ransomware: Locks or encrypts your files and demands payment.
• Rootkit: Hides malicious activity deep in the OS.

Symptoms of Infection

• Slow or unstable system performance
• Frequent crashes or BSODs
• Pop-ups or unwanted browser redirects
• Disabled antivirus or Windows Defender
• Unknown programs or high network usage
• Files disappearing or encrypted with strange extensions

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🧭 2. Step-by-Step Malware Troubleshooting Process

Step 1: Isolate the Infected System

Before doing anything else:

1.     Disconnect the PC from the internet and local networks to prevent spreading malware.

2.     Do not plug in USB drives or external devices.

3.     If the PC is part of a company network, notify IT support immediately.

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Step 2: Boot into Safe Mode

Safe Mode runs Windows with minimal drivers — preventing most malware from starting.

To enter Safe Mode:

1.     Hold Shift and click Restart.

2.     Choose Troubleshoot → Advanced Options → Startup Settings → Restart.

3.     Press 4 (Safe Mode) or 5 (Safe Mode with Networking)** if you need to download tools.

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Step 3: Run Windows Defender Offline Scan

Windows Defender has a powerful offline scan that runs before Windows fully loads, catching deep-rooted malware.

1.     Go to:
Settings → Privacy & Security → Windows Security → Virus & Threat Protection.

2.     Select Scan options → Microsoft Defender Offline scan → Scan now.

3.     The PC will restart and scan the entire system before booting into Windows.

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Step 4: Use Reputable Anti-Malware Tools

In Safe Mode or offline, run one or more of these trusted tools:

Tool	Purpose
Malwarebytes	Deep malware and adware removal
ESET Online Scanner	Cloud-based full system scan
Kaspersky Virus Removal Tool	Detects hidden threats
AdwCleaner	Removes browser hijackers and adware
HitmanPro	Cloud-assisted detection for stubborn malware

💡 Tip: Always download tools directly from official websites to avoid fake or infected versions.

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Step 5: Delete Temporary and Suspicious Files

After removing malware, clean leftover junk:

1.     Open Run (Windows + R) → type:

2. temp

3. %temp%

4. prefetch

5.     Delete all contents in these folders.

6.     Run Disk Cleanup or Storage Sense to remove system junk and quarantined files.

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Step 6: Restore Damaged System Files

Malware may corrupt Windows core files. Use built-in tools to repair them.

Run System File Checker:

sfc /scannow

Then run DISM to fix deeper corruption:

DISM /Online /Cleanup-Image /RestoreHealth

These commands verify and replace missing or infected Windows files.

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Step 7: Check Startup Programs and Services

Malware often adds itself to startup processes.

1.     Press Ctrl + Shift + Esc to open Task Manager.

2.     Go to the Startup tab → Disable any unknown or suspicious entries.

3.     Open Run → msconfig → Services tab → Hide Microsoft services → Uncheck unknown ones.

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Step 8: Reset Web Browsers

Malware frequently changes browser settings or installs extensions.

For Chrome:

• Go to Settings → Reset settings → Restore settings to their original defaults.

For Edge:

• Settings → Reset settings → Restore settings to their default values.

For Firefox:

• Help → More Troubleshooting Information → Refresh Firefox.

Also, clear all browser caches, cookies, and saved passwords if compromised.

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Step 9: Check Windows Registry (Advanced Users)

Malware can modify registry keys to persist after reboots.

⚠️ Caution: Editing the registry incorrectly can damage your system.

1.     Press Windows + R, type:

2. regedit

3.     Check the following keys for unusual entries:

o    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

o    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

Delete only entries that clearly reference known malware names or invalid file paths.

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Step 10: Review Scheduled Tasks

Some malware re-infects systems through scheduled tasks.

1.     Open Task Scheduler.

2.     Go to Task Scheduler Library.

3.     Delete any suspicious tasks (especially those created recently or without clear purpose).

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Step 11: Re-enable Security Features

After cleanup:

• Turn Windows Defender Real-Time Protection back on.
• Enable Firewall:

·         Control Panel → Windows Defender Firewall → Turn on

• Run Windows Update to ensure all security patches are applied.

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Step 12: Restore or Reinstall Windows (If Needed)

If malware caused severe damage or encryption (e.g., ransomware):

1.     Back up clean files (after scanning with antivirus).

2.     Use System Restore:

3. Control Panel → Recovery → Open System Restore

4.     Or Reset This PC under:

5. Settings → System → Recovery → Reset this PC

6.     If still compromised, reinstall Windows using official media.

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🧩 3. Verifying System Integrity After Cleanup

• Check Windows Security Dashboard for any remaining threats.
• Run:

·         netstat -an

to look for unknown network connections.

• Use Autoruns (from Microsoft Sysinternals) to confirm no malicious startup entries remain.
• Monitor system performance for at least a few days to ensure stability.

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🧠 4. Prevention Tips for the Future

✅ Best Practices

• Keep Windows and apps updated regularly.
• Use real-time antivirus protection (Windows Defender is excellent).
• Avoid clicking on suspicious email links or attachments.
• Download software only from official or verified sources.
• Enable Controlled Folder Access to protect important files.
• Use Standard user accounts instead of admin for daily use.
• Maintain regular backups to an external drive or cloud storage.

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🧾 5. Recommended Tools Summary

Tool	Purpose	Type
Microsoft Defender Offline	Built-in deep malware scan	Free
Malwarebytes	Real-time and manual malware removal	Free / Paid
ESET Online Scanner	Quick cloud scan	Free
AdwCleaner	Removes browser hijackers	Free
HitmanPro	Advanced behavioral detection	Paid / Trial
Autoruns	Detects startup persistence	Free

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🏁 Conclusion

Troubleshooting malware-infected Windows systems safely requires isolation, scanning, cleanup, and repair. Always start in Safe Mode, run offline antivirus tools, and ensure system files are restored.

By combining these techniques with regular backups and updates, you can eliminate infections completely and keep your Windows system secure from future threats.

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Written by: UltraTechGuide
For more system repair and cybersecurity tutorials, visit: ultratechguide.blogspot.com