How to scan for malware
Real-time protection checks files and programs on the disk as they are accessed and it is invaluable in protecting the computer from infection. It is the first line of defence.
Files that are not accessed, such as downloads you have not you got around to looking at, or which you downloaded a long time ago, could harbour malware and so it is useful to scan the disk to see if there are any potential problems and deal with them.
1 Start Windows Defender
We saw earlier that Windows Defender could be started from within the Settings app. It is not the only way to start it.
Right click the Start button and select Control Panel on the menu that is displayed.
Set View by in the top right corner to Small icons.
Look down the list of items and near the bottom is Windows Defender. Click it to run it.
Another way to run Windows Defender is to click in the search box in the taskbar and type 'windows defender'. Click it in the search results that are displayed. It is usually at the top.
There are three tabs in Windows Defender, Home, Update and History. Select Home if it is not already selected and on the left it shows whether real-time protection is on and whether the virus and spyware definitions are up to date.
2 Select a scan option
On the right are three scan options:
Quick: A quick scan should be performed every week. Select the option and click the Scan now button. This type of scan is faster than a Full scan because only the parts of the disk drive that are most at risk are scanned for malware. It is sufficient to catch most malware.
Full: A full scan takes longer, but it is more thorough and more likely to find malware. This is because it looks at every part of the disk drive and not just in the obvious locations. Run a full scan once a month.
Custom: This option enables a drive or folder to be selected and the contents are then scanned. You might want to use this to scan a USB flash memory drive (thumb drive or pen drive), or an external USB disk drive.
3 Perform a custom scan
Select Custom scan, click Scan now, then select the disk or folder by expanding the disks. Click the tick box to select folders and disks.
4 Scan folders
A different way to perform a custom scan is to right click a folder or drive in Explorer and select Scan with Windows Defender. The advantage of this method is that you don’t need to find and Start Windows Defender. It does not need to be running, just right click and scan.
You can continue to use the computer while Windows Defender is scanning, but it can make it run more slowly, so you might want to scan when you are not doing anything important. A full scan can take an hour or more.
Hopefully, nothing will be found, but if it is, it will be dealt with.
5 Scan offline with Windows Defender
If you can for malware and either it cannot be removed or if you scan again and it is still finding malware, there is a more powerful removal method available. Press Windows+I to open the Settings app, click Update & security, select Windows Defender on the left and then find Windows Defender Offline on the right. Close any programs or windows you have open and click Scan Offline.
Windows will shut down and the computer will restart. As it does so, Windows Defender will scan the system and remove any malware found.
Previous: How to update Windows Defender
Course Contents: Windows 10 Security Guide