Signs Your Computer Has a Virus
How to tell malware from a normal slowdown — and what to do about it.
- Security
- By Ray Berro, Tech4Service
Not every slow computer is infected, but certain signs strongly suggest malware. Knowing the difference helps you respond correctly.
Common infection signs
- Sudden pop-ups, fake virus warnings, or "tech support" scare screens
- Browser homepage or search engine changed without your action
- New toolbars, extensions, or programs you didn't install
- Unusual network activity, fan running constantly, or overheating at idle
- Files encrypted or renamed (possible ransomware) — act immediately
Slowdown vs infection
A gradual slowdown over years is often just full storage or an aging hard drive — see our slow computer guide. A sudden change in behaviour is more likely malware.
What to do
Disconnect from the internet, avoid entering passwords, and don't pay any "support" number on a pop-up — those are scams. Follow our malware removal guide or bring it in for a full cleanup.
Professional cleanup
Our virus & malware removal goes beyond a single scan: we remove persistence, reset browsers, verify DNS integrity, and harden security so it doesn't come back.
Common Questions
When should I stop troubleshooting and book a repair?
If the problem appeared suddenly, involves hardware sounds (clicking, grinding), liquid damage, or persists after safe software steps — book a diagnostic. We'll confirm the fix and price before work begins.
How much does professional repair cost?
Most repairs fall in the $89–$250 range after diagnostics. See our pricing page or book a free basic diagnostic on most drop-off repairs.
Rather leave it to a pro?
Book a diagnostic — we'll confirm the fix, price, and timeline. 30-day labour warranty on completed repairs.