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Expert repairs, upgrades, and IT support for homes and businesses across Henley and the surrounding area.

Open Mon–Fri, 10am–5pm · 6 Hart Street, RG9 2AU

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Security · 6 min read

How to Tell If Your PC Has a Virus

Pop-ups, strange behaviour, slow performance — here's what to look for and what to do about it.

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Computer viruses and malware have become increasingly sophisticated. Some run silently in the background for months — stealing data, sending spam, or mining cryptocurrency — without you noticing until the damage is done.

Warning signs your PC may be infected

Suddenly much slower than usual — especially at startup
Pop-up adverts appearing even when you're not browsing
Browser homepage or search engine changed without your permission
New toolbars or extensions you didn't install
Programmes crashing or freezing frequently
Hard drive constantly active (light flashing) even when idle
Friends say they're receiving strange emails from you
Antivirus has been disabled or won't open
Ransom messages or warnings you can't close

What to do right now

If you suspect an infection:

Disconnect from the internet (unplug the cable or turn off Wi-Fi)
Don't enter any passwords or do online banking
Run a full scan with Windows Defender if you can open it
Don't pay any ransom demands — contact us first

How we clean an infected PC

At Henley Computer Repairs we run a thorough multi-tool cleaning process, remove all traces of malware, check for keyloggers and spyware, and set up proper ongoing protection so it doesn't happen again. We also advise you on safe browsing habits and which free antivirus tools are genuinely effective.

Prevention is better than cure

Keep Windows updated, use a reputable antivirus (Windows Defender is actually very good), avoid clicking email attachments from unknown senders, and never download software from unofficial sites. And always — always — keep a backup.

Think your PC is infected? Bring it in to 6 Hart Street or message us on WhatsApp →

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We're open Mon-Fri 10am-5pm, based in the centre of Henley-on-Thames.

Email Paul WhatsApp 01491 523100