To delete viruses from a computer, isolate the device, run reputable scans (including an offline scan), remove threats, then patch and reset risky settings.
Worried your PC or Mac picked up malware? This guide shows you how to delete viruses from a computer without guesswork. You’ll see the exact order of actions, when to use special scans, and what to reset so infections don’t sneak back.
How To Delete Viruses From A Computer: Step-By-Step Plan
Follow these steps in order. Skipping around can leave leftovers or hide the real entry point.
1) Disconnect And Stabilize
- Unplug Ethernet. Turn off Wi-Fi and Bluetooth.
- If you see fake alerts, don’t click the buttons. Close the window via Task Manager (Windows) or Force Quit (macOS).
- Plug the machine into power so scans can run end-to-end.
2) Update Security Intelligence
Before scanning, refresh threat definitions. On Windows, open Windows Security → Virus & threat protection → Check for updates. On a Mac, make sure macOS is current and keep built-in protections (Gatekeeper, XProtect) on.
3) Run A Full Scan First
Start with a full system scan. It takes longer than a quick scan, but it sweeps more locations and sets a baseline. Quarantine anything flagged; don’t delete yet—you might need to restore a false positive.
Quick Actions And Where To Find Them
| Removal Action | Where To Find It | What It Does |
|---|---|---|
| Full Scan | Windows Security → Virus & threat protection → Scan options | Checks all files and running processes |
| Microsoft Defender Offline | Windows Security → Scan options → Offline scan | Boot-level scan to catch hidden threats |
| Safe Mode | Windows: Settings → Recovery → Advanced startup; Mac: Restart & hold Shift | Starts with minimal items to unblock cleanup |
| Startup Items Review | Windows: Task Manager → Startup; Mac: System Settings → Login Items | Disables shady auto-starts |
| Browser Reset | Chrome/Edge/Firefox/Safari settings | Removes rogue extensions and hijacks |
| System Update | Windows Update / macOS Software Update | Closes exploited holes |
| Restore From Clean Backup | File History / Time Machine / image backup | Rolls back to a known-good state |
| Factory Reset (Last Resort) | Windows Reset this PC / macOS Erase All Content | Wipes the system and reinstalls |
4) Use Safe Mode To Unstick Stubborn Items
If the full scan stalls or the same item keeps returning, reboot to Safe Mode and scan again. With fewer processes running, malware has less room to hide.
5) Run An Offline Scan On Windows
An offline scan runs before Windows fully loads, which helps catch rootkits and deeply hooked pests. In Windows Security, open Scan options and pick Microsoft Defender Offline; the PC will restart and scan outside the normal desktop.
6) Clean Up Startup, Schedulers, And Services
- Windows: open Task Manager → Startup apps. Disable junk you don’t recognize. In Services, set suspicious entries to Disabled until you confirm their purpose.
- macOS: System Settings → Login Items. Remove unknown launch agents or daemons. Use a reputable process viewer if needed.
7) Reset Browsers
Adware often lives in extensions and policies. Remove extensions you didn’t install, reset the default search engine, and clear policies. In Chrome and Edge, use Reset settings. In Safari, remove profiles you don’t recognize.
8) Patch The System
Install pending Windows Updates or macOS updates, then update browsers, Java runtimes, game launchers, and office suites. Many outbreaks ride old plug-ins.
9) Re-scan And Only Then Delete
Run another full scan. If items are still quarantined on repeat, they’re likely real. Export a log, then remove them. If a needed file was flagged, restore and upload it to a multi-scanner for a second opinion before keeping it.
Taking Viruses Off Your PC Or Mac: What To Do Differently
Windows and macOS share the same cleanup logic, but a few platform moves differ.
Windows: Built-In Tools That Work
- Windows Security. Run a full scan, then an offline scan if threats persist. Use Protection history to review actions and file paths.
- Reset This PC. If system files are trashed and scans keep finding leftovers, use Reset this PC with Keep my files first. If the issue survives, choose Remove everything and restore from a clean backup.
macOS: Built-In Protections
- Gatekeeper and XProtect. Keep them on. Avoid disabling them for unsigned apps.
- Safe Mode on Mac. Restart while holding Shift, log in, and you’ll see “Safe Boot” in the menu bar. Remove shady login items and profiles, then run your scanner of choice.
Deleting Viruses From Your Computer: Rules That Work
These habits cut infection time and keep cleanup short.
Lock Down Entry Points
- Install apps from trusted stores or direct from known vendors.
- Don’t run installers from pop-ups or random mirrors.
- Block macros by default unless your workflow needs them.
Make Browser Hygiene A Routine
- Use a single, reputable ad-blocker. Avoid bundles of “security” extensions.
- Turn on site isolation and tighten cookies to “block third-party” where possible.
- Clear downloads and remove old installers monthly.
Build A Clean-Image Escape Hatch
Keep a fresh system image or Time Machine snapshot taken after patching and driver installs. If a bad day hits, you can restore to this baseline in minutes.
When An Offline Scan Or Safe Mode Isn’t Enough
Some infections wedge deep. Use these escalation points as a checklist.
Escalation Checklist
- Repeat offline scan. Two passes with reboots can catch late droppers.
- Audit scheduled tasks. Remove entries that re-spawn scripts, miners, or browser policies.
- Look for odd network tasks. Unknown Updaters or “Helper” items that phone home deserve a closer look.
- Switch accounts. Create a new admin, sign out of the old account, and perform scans again to cut user-level persistence.
- Factory reset last. Back up files, sign out of accounts, and wipe only after you’ve exported logs and keys you’ll need later.
On Windows, the Microsoft Defender Offline scan runs before the desktop loads and is designed to catch entrenched threats. On macOS, Apple documents how macOS blocks known malware with XProtect and related tooling in Protecting against malware in macOS.
Telltale Signs You Need A Deeper Clean
Not every slowdown is malware. The pattern below leans toward infection.
Symptoms, Likely Causes, And Fast Fixes
| Symptom | Likely Cause | Fix |
|---|---|---|
| Browser home/search keeps changing | Extension or policy hijack | Reset browser; remove extensions; clear policies |
| Pop-ups even with no browser open | Adware service or startup item | Disable startup items; scan in Safe Mode |
| Fans race at idle | Miner or hidden updater | Check Task Manager/Activity Monitor; kill and scan |
| Security app won’t start | Interference by malware | Run offline scan; repair app; patch OS |
| Files locked with new extensions | Ransomware | Isolate device; do not pay; restore from backup |
| Unknown admin account appears | Persistence via new user | Remove account; rotate passwords; re-scan |
| Frequent redirects to fake scanners | DNS or proxy change | Reset network stack; check hosts/DNS settings |
How To Delete Viruses From A Computer Without Losing Data
You can clean safely and keep personal files. The trick is staging the work.
Back Up Smart
- Copy documents, photos, and project folders to an external drive or cloud drive while the machine is offline.
- Avoid backing up program folders or unknown executables.
- Scan the backup from a second, clean device before restoring it.
Reset Without Wiping
Windows: use Reset this PC → Keep my files to reinstall system files while preserving user folders. Mac: keep a recent Time Machine snapshot and migrate user data after a clean reinstall if needed.
Prevent The Next Infection
Once clean, set a few guardrails so the same trick doesn’t work again.
Patch Rhythm
- Enable auto updates for the OS.
- Keep browsers, PDF tools, and office suites current.
- Uninstall software you don’t need; fewer apps, fewer holes.
Safer Downloads
- Grab installers from the vendor page or trusted stores.
- Verify checksums or signatures when offered.
- Be wary of “free” codec packs and supposed driver updaters.
Account And Data Hygiene
- Use a standard account for daily work; keep an admin account only for installs.
- Turn on two-factor where available.
- Keep offline backups that ransomware can’t reach.
When To Call In Reinforcements
Some red flags point to a wider breach: repeat ransomware, unknown remote tools, or lateral movement on your home network. If you spot these, isolate every device, change account passwords from a known-clean machine, and rebuild the system from trusted media. Organizations should follow an incident playbook and involve qualified responders.
FAQ-Free Wrap-Up You Can Act On
You’ve learned how to delete viruses from a computer, when to switch to Safe Mode or an offline scan, and how to harden the machine so the same trick doesn’t work again. Keep the steps handy, keep backups current, and treat odd prompts or “cleaners” you didn’t ask for as red flags. Clean methodically, then patch and move forward.