Think Your Computer Has a Virus?
Here's What to Do

Something feels off. Your computer is acting weird — pop-ups appearing out of nowhere, programs you don't recognize, your browser going places you didn't ask it to go. You've got that sinking feeling: I think I have a virus.

At PC Medics of NJ, we remove viruses and malware from computers every single week. Some infections are minor annoyances. Others are serious enough to steal your passwords, encrypt your files, or drain your bank account. The good news? If you act quickly and know what to look for, you can limit the damage and often fix the problem entirely.

Here's your step-by-step guide.

1 Warning Signs Your Computer Is Infected

Viruses and malware don't always make themselves obvious. Sometimes the only sign is that your computer feels "off." But here are the most common red flags we see in our shop:

• Unexpected pop-ups — especially ones telling you your computer is infected and urging you to call a number or download software. Ironically, these pop-ups are often the virus itself.
• Dramatically slower performance — your computer was fine last week, and now everything takes forever. Malware running in the background eats CPU and memory.
• Unfamiliar programs or toolbars — software you didn't install appearing on your desktop or in your browser is a classic sign of adware or bundled malware.
• Browser redirects — you search for something on Google and end up on a sketchy site, or your homepage changed without your permission.
• Your antivirus is disabled — many viruses will quietly turn off Windows Defender or other security software as one of the first things they do.
• Friends receiving strange emails or messages from you — if people tell you they got a weird link from your account, your system or email may be compromised.
• Unusual hard drive or network activity — fans spinning up with nothing open, or your internet feeling slower than it should, can mean something is working behind the scenes.

2 What to Do Immediately

If you suspect your computer is infected, here's what to do right now — before trying to fix anything:

• Disconnect from the internet. Unplug your ethernet cable or turn off Wi-Fi. This stops malware from sending your data out, downloading more malicious files, or spreading to other devices on your network.
• Don't log into anything sensitive. No banking, no email, no shopping. If a keylogger is running, it's recording everything you type.
• Don't install random "antivirus" software from pop-ups. Those are almost always scams themselves. Only use trusted tools from known sources.
• Write down what happened. When did things start acting weird? Did you click a link, download a file, or open an email attachment? This helps us (or any technician) figure out what type of infection you're dealing with.

3 Free Tools That Can Help

If the infection seems manageable — your computer still works, you can open programs, and you're not locked out — these free tools are a good starting point:

Malwarebytes Free — This is our go-to recommendation. Download it from malwarebytes.com (on a clean computer if needed, then transfer via USB). Run a full scan. Malwarebytes catches a lot of things that Windows Defender misses, especially adware, browser hijackers, and potentially unwanted programs.

Windows Defender (built into Windows 10 and 11) — It's already on your computer and it's genuinely good in 2026. Make sure it's turned on and up to date, then run a full scan (not just a quick scan). For deeper infections, try the "Microsoft Defender Offline scan" option, which reboots your computer and scans before Windows fully loads — catching malware that hides while Windows is running.

AdwCleaner (by Malwarebytes) — A lightweight, no-install tool that specifically targets adware, browser hijackers, and toolbars. Great for cleaning up a browser that's been taken over.

4 A Word About Ransomware

Ransomware is in a category of its own. It encrypts your files — documents, photos, everything — and demands payment (usually in cryptocurrency) to give them back. If you see a full-screen message telling you your files are locked and you need to pay, here's what you need to know:

• Do NOT pay the ransom. There is no guarantee you'll get your files back. Many victims pay and receive nothing. You're also funding criminal operations.
• Disconnect immediately — from Wi-Fi, ethernet, and any external drives or USB devices. Ransomware can spread to connected drives and network shares.
• Take a photo of the ransom screen. This helps identify the specific ransomware variant, which matters for recovery options.
• Call a professional. Some ransomware strains have known decryption tools available for free. A technician can identify the variant and check if a solution exists.

5 When to Call a Professional

The free tools above work great for minor infections. But there are times when you really should bring your computer to someone who does this for a living:

• The virus keeps coming back after you scan and remove it. Some malware embeds itself deep in the system and reinstalls itself.
• You're locked out of your computer or can't boot into Windows at all.
• You suspect your personal information has been stolen — passwords, banking info, Social Security numbers.
• Your business computer is infected and you can't afford downtime or data loss.
• You're not confident doing it yourself — and that's completely fine. There's no shame in it. Removing malware the wrong way can sometimes make things worse.

At PC Medics of NJ, we do thorough virus and malware removal that goes beyond just running a scan. We check for rootkits, verify your system files haven't been tampered with, clean up the registry, make sure your security software is properly configured, and check that nothing is phoning home to a remote server. We also help you understand how the infection happened so you can avoid it next time.

Stay Safe Out There

Most virus infections happen because someone clicked something they shouldn't have — a fake email link, a sketchy download, a "you've won" pop-up. The best protection is a combination of good habits, updated software, and a reliable backup.

But if the damage is already done, don't stress. It's fixable. Bring your computer to PC Medics of NJ or give us a call. We'll clean it up, lock it down, and get you back to normal — usually within the same day.