Signs Your Computer Has a Virus — Check These First
Symptom
Likely Cause
Urgency
Browser homepage or search engine changed
Browser hijacker
?? Medium — fix browser settings
Constant pop-up ads on all websites
Adware
?? Medium — scan with Malwarebytes
PC extremely slow, fans running constantly
Cryptominer or trojan
?? High — scan immediately
Antivirus disabled or cannot open security tools
Trojan or rootkit
?? High — boot into Safe Mode
Files encrypted, ransom note on screen
Ransomware
?? Critical — disconnect from internet now
Friends report strange emails from your account
Email account compromised
?? High — change passwords immediately
Programs you did not install appear
PUP or trojan
?? Medium — uninstall and scan
This guide covers:
how to remove virus from computerhow to remove malwareremove virus Windows 10remove virus Windows 11how to remove adwarebrowser hijacker removalmalwarebytes virus removalhow to get rid of a viruscomputer virus symptomsscan for malware freehow to remove trojanransomware removal
Step 1 — Disconnect from the Internet
As soon as you suspect a virus, disconnect from the internet — turn off Wi-Fi or unplug the Ethernet cable. This stops the malware from: sending your data to attackers; receiving commands from its control server; downloading additional malware; spreading to other devices on your network. Do not reconnect until the cleaning steps are complete.
Step 2 — Boot into Windows Safe Mode
Safe Mode starts Windows with only essential system processes — most malware cannot run in Safe Mode because it is prevented from loading at startup. This makes it much easier to detect and remove.
Windows 10 / Windows 11 — Safe Mode Steps
Click Start ? Power ? Restart while holding the Shift key
After restart, press F5 to boot into Safe Mode with Networking
Windows will restart in Safe Mode — the screen looks different (lower resolution, black background) — this is normal
Why Safe Mode with Networking? You need internet access to download Malwarebytes if you have not already. Safe Mode with Networking allows this while blocking most malware from running.
Step 3 — Scan and Remove with Malwarebytes Free
Malwarebytes Free is the best free malware removal tool — excellent at finding adware, PUPs, browser hijackers, trojans, and other threats that traditional antivirus sometimes misses.
When the scan completes, click Quarantine to remove everything found
Restart the computer when prompted
Step 4 — Run Windows Defender Full Scan
After Malwarebytes, run a second scan with Windows Defender (built-in, free) as a second-opinion check:
Open Windows Security (search in Start menu)
Click Virus & threat protection ? Scan options
Select Full scan and click Scan now
A full scan takes 30 minutes to several hours — do not interrupt it
If threats are found, click Start actions to remove them
Why run both? Malwarebytes and Windows Defender use different detection methods. Running both catches threats that either tool alone might miss. This two-scanner approach is the industry-standard recommendation for cleaning an infected PC.
Step 5 — Remove Suspicious Programs
Go to Settings ? Apps ? Installed apps (Windows 11) or Settings ? Apps & Features (Windows 10)
Sort by Install date to see recently installed programs
Uninstall any programs you do not recognise or did not intentionally install — right-click ? Uninstall
Common suspicious program names to look for: “Search Manager”, “PC Optimizer Pro”, “Web Companion”, anything with “Toolbar”, and software you have no memory of installing
Step 6 — Fix Your Browser (Remove Browser Hijacker)
If your browser homepage or search engine was changed, reset it after removing the malware:
Google Chrome
Click the three dots menu ? Settings ? Reset and clean up ? Restore settings to their original defaults
Click Reset settings — this removes extensions, resets homepage and search engine
Microsoft Edge
Three dots menu ? Settings ? Reset settings ? Restore settings to their default values
Mozilla Firefox
Click the menu ? Help ? More troubleshooting information ? Refresh Firefox
Step 7 — Change Your Passwords
After confirming your PC is clean, change passwords for all important accounts — email, banking, social media, and any accounts that store payment information. Do this from a clean device or after the PC has been cleaned and rebooted normally. If a keylogger was installed, it may have captured passwords you typed while infected. Use a password manager to generate and store new strong passwords.
Special Case: Ransomware
If your files have been encrypted by ransomware and you see a ransom note:
Do This
Disconnect from internet immediately
Check nomoreransom.org for free decryption tools
Report to local cybercrime authorities
Restore from a pre-infection backup if you have one
Contact a professional cybersecurity firm if critical data is at stake
Do Not Do This
Do NOT pay the ransom — no guarantee of decryption
Do NOT restart the computer immediately — may trigger additional encryption
Do NOT delete encrypted files — wait for free decryptors
Do NOT connect backup drives while infected — they may get encrypted too
Common signs of a computer virus or malware infection: (1) Your PC is significantly slower than usual — malware runs background processes that consume CPU and RAM. (2) Your browser homepage or default search engine has changed without your permission — sign of a browser hijacker. (3) Unexpected pop-up ads appearing on all websites or on the desktop — sign of adware. (4) Programs crash more frequently or the system freezes. (5) Your antivirus has been disabled or you cannot open antivirus or security tools. (6) Files or programs you did not install appear on your computer. (7) Your friends report receiving strange emails or messages from your accounts. (8) High network activity when you are not downloading anything.
For removing browser hijackers and adware (the most common PC malware): yes — you can uninstall suspicious programs via Windows Settings > Apps, reset your browser settings, and run Windows Defender (built-in, free). For removing trojans, ransomware, or rootkits: practically, no — these embed themselves deep in the system and require dedicated security tools like Malwarebytes Free or your primary antivirus to detect and remove safely. Windows Defender (built-in) can remove many common threats without installing third-party software.
A factory reset is a last resort, not a first step. Try running Malwarebytes Free and your primary antivirus first — these remove the vast majority of malware without losing your data. If malware persists after two rounds of scanning and removal, or if you have been infected with ransomware that has already encrypted files, a factory reset (while backing up clean files first) may be necessary. Always back up photos, documents, and important files to an external drive before factory resetting. After resetting, restore only data files — never restore a full system image backup that was made while infected.
Malware is the umbrella term for all malicious software. A virus is a specific type of malware that attaches itself to legitimate files and spreads to other files when those files are opened — one of the oldest malware types. Spyware secretly monitors your activity and sends data (keystrokes, passwords, browsing history) to attackers without you knowing. Ransomware encrypts your files and demands payment. Adware floods browsers with unwanted ads. Trojans disguise themselves as legitimate software to gain system access. Rootkits hide deeply in the operating system to avoid detection. In everyday speech, “virus” is used loosely to mean any type of malware — your antivirus software protects against all of these.
Yes — Windows Security (Microsoft Defender) is built into Windows 10 and Windows 11 and is active by default. It provides real-time malware protection, a firewall, SmartScreen phishing protection, and ransomware folder protection. It runs automatically without any setup. However, independent tests from AV-Test and Consumer Reports consistently find that dedicated antivirus tools (Bitdefender, Avira, Avast) deliver higher malware detection rates than Defender alone. For most careful users, Defender is adequate baseline protection. For higher-risk users or anyone who wants maximum protection, adding a dedicated antivirus improves detection noticeably.
Yes — Macs do get malware, though less frequently than Windows PCs. The most common Mac malware types are adware (unwanted ads in browsers), browser hijackers (changing homepage and search engine), PUPs (potentially unwanted programs bundled with other software), and information-stealing trojans like Atomic Stealer. macOS includes XProtect and Gatekeeper for basic protection but these only detect known malware after Apple updates their definitions. See our guide: Best Antivirus for Mac for the most effective Mac malware removal tools.
The most common ways malware infects PCs: (1) Downloading pirated software or cracked games — these often contain hidden malware. (2) Clicking malicious email attachments — phishing emails disguised as invoices, delivery notifications, or bank alerts. (3) Installing fake software updates — pop-up warnings claiming your Flash Player or Java needs updating. (4) Visiting compromised websites — drive-by downloads infect PCs through browser vulnerabilities. (5) Clicking links in suspicious text messages or social media messages. (6) Installing software bundled with adware — free software that includes PUPs in the installation by default.
Best practices to prevent future malware infections: (1) Install a reputable antivirus with real-time protection — Bitdefender or Norton for paid, Avira or Windows Defender for free. (2) Keep Windows updated — Windows Update patches security vulnerabilities that malware exploits. (3) Never download software from unofficial sources or piracy sites. (4) Never click email attachments from unknown senders — verify unusual attachments by phone with the sender. (5) Use a password manager to avoid phishing — it only autofills on the legitimate website domain. (6) Use a VPN on public Wi-Fi to prevent network-level attacks. (7) Back up important files regularly to an external drive or cloud — protection against ransomware.
Conclusion — How to Remove a Virus from Your Computer
Most malware infections can be fully removed by following the 7 steps above: disconnect from internet, Safe Mode, Malwarebytes Free scan, Windows Defender full scan, remove suspicious programs, reset browser, change passwords. The two-scanner approach (Malwarebytes + Windows Defender) catches the vast majority of infections. For ransomware, check nomoreransom.org for free decryptors before considering payment. To prevent future infections, install a real-time antivirus — see our full comparison: Best Antivirus Software.
Create trends that set your business apart and attract a wider audience. Connect with potential customers by showcasing your unique offerings, building credibility, and personalizing every interaction.
Leave a Comment