This week we've covered a lot of ground. Junk that comes pre-installed on new computers. Fake cleaning tools that don't do what they promise. Phishing emails designed to steal your information. Scareware pages that lock your screen and blast an alarm.

All of it was built around one common thread: things that look scary but usually aren't.

But here's the flip side of that. Sometimes something actually is wrong. Real infections do happen, and knowing how to tell the difference between a genuine problem and a fake scare is one of the most useful things you can learn.

So let's talk about what a real computer infection actually looks like, how to check for one the right way, and what to do if you find something.

What a Real Infection Actually Looks Like

Real malware tends to be quiet. That's what makes it effective. Unlike the screaming pop-up from a scareware page, actual malicious software doesn't usually announce itself. It's trying to stick around without being noticed.

Here are some genuine warning signs worth paying attention to:

Your computer is suddenly much slower for no obvious reason. Not slightly slower, but noticeably dragging even when you're not doing anything demanding.

Your browser is behaving strangely. A different homepage appeared that you didn't set. Your searches are being redirected to sites you've never heard of. New toolbars showed up on their own.

Programs are opening or running that you didn't start. You see activity in the corner of your screen, or your hard drive light is going constantly even when the computer seems idle.

Your contacts are getting emails or messages from you that you didn't send. This one is serious and means something has access to your accounts.

Your antivirus is turned off and you can't turn it back on. Some malware specifically targets security software because it knows that's what would catch it.

A fake pop-up on a website is not on this list. Neither is a slow startup caused by too many apps loading at once. Context matters.

How to Actually Check

If you're seeing real warning signs, here's the right way to check, using tools that are free and trustworthy.

Step one: Run Windows Defender.

Windows Defender is built into every copy of Windows 10 and 11. Open it by clicking the Start button and searching for "Windows Security." Select Virus and Threat Protection, then click Quick Scan. If it finds something, follow the prompts to remove it. If you want a more thorough check, select Scan Options and choose Full Scan instead. It takes longer but looks everywhere.

Step two: Run Malwarebytes.

Malwarebytes is a well-respected second opinion. The free version is all you need. Download it directly from malwarebytes.com, install it, and run a scan. It's good at catching things that other tools sometimes miss, particularly adware and browser hijackers.

Running both gives you a thorough check without spending a penny.

What to Do If Something Is Found

If either tool finds and removes something, that's actually the best-case outcome. The tool did its job. Once it's removed, change the passwords for your email and any accounts you use on that computer, starting with the most important ones. If you do any banking on that machine, let your bank know what happened.

If the tools find something but can't remove it, or if you keep seeing the same thing come back after removal, that's a sign the infection is more deeply embedded. That's when it makes sense to bring it in rather than chase it yourself.

What to Do If Nothing Is Found

If you ran both scans and came up clean, your computer is almost certainly fine. Whatever you were seeing was probably one of the fakes we talked about this week, a slow startup, a browser notification you accidentally allowed, or a scareware page you stumbled onto.

That's genuinely good news, even if it doesn't feel like it in the moment.

The Honest Bottom Line

Most people who think they have a virus don't. Most scary-looking alerts are tricks. But when something real is going on, your computer usually tells you in ways that are a lot less dramatic than a flashing red screen and a blaring alarm.

Trust the quiet signs more than the loud ones. Check with real tools, not ones you found through a scary pop-up. And if you're ever not sure, we're happy to take a look and give you a straight answer.

That's what we're here for.

That wraps up this week. Thanks for reading along. Check back Monday for a fresh start.