On occasion, it’s a good idea to run a complete anti-malware scan of your computer.
In Windows 10, it’s easy to do, using Windows Security (previously known as Windows Defender). I’ll walk you through the steps.
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- Click on the Windows Security icon in the taskbar notification area.
- Click on Virus & threat protection.
- Click on Scan options.
- Click on Full scan.
- Click on Scan now.
Consider a full scan whenever your machine is acting up or you suspect malicious behavior.
Step by step
We start in the Windows taskbar notification area.
Click on the Windows Security icon (you may need to click the caret in the taskbar — “^” — to expose the icon).
Click on Virus & threat protection.
Click on Scan options.
Click on Full scan, and then click on Scan now.
The anti-malware scan begins. Exactly how long this will take varies based on what else your computer is doing at the time, how fast it is, and how much data is stored.
Why run a full scan?
Full scans are not something you need do often. Most of the time, Windows Security’s own periodic quick scan, coupled with its real-time components scanning things as they change or are downloaded, is enough.
On the other hand, sometimes you need more. “Quick scan” is quick because it doesn’t scan absolutely everything. It limits its scope to files and folders on the disk that are the most common targets of malicious software. Other areas where malware rarely resides are bypassed.
But rarely isn’t never.
I recommend a full scan if you suspect malware has made it to your machine somehow. If your machine is misbehaving, slow, or there are just odd things happening, a full scan is a comparatively quick way to rule out malicious software as the cause.
Other scan types
You’ll note that in addition to “quick” and “full”, there’s also “custom” and “Microsoft Defender Offline scan”.
Custom scans allow you to specify the folder to be scanned. This is a fine option if you’ve just downloaded something and you want the additional reassurance of a manual scan. Point Windows Security at the Downloads folder using a custom scan.
Microsoft Defender Offline addresses the case where malware is undetectable or unremovable because it has somehow incorporated itself into Windows system files. The only way to deal with malware of this sort is to scan when Windows isn’t running. The only way to do that is to boot into something other than Windows to perform the scan.
That’s Microsoft Defender Offline. It will reboot your machine into a dedicated recovery mode to run the anti-malware software without Windows running. It’s a useful tool if you find you have malware that can’t be removed, or suspect malware is present even when a full scan reports none to be found.