Despite weekly and monthly scheduled scanning, you might need to scan your computer in case you have any doubts. You can either scan just one file or folder or perform any default or custom scan whenever you need to.
Scanning just one file or folder takes less time, but to be really sure your computer is not infected you might need to perform a full scan.
To scan just one file or folder (aka directory), right-click the item in Windows Explorer and select Scan <item name>. You can also select multiple items using Shift or Ctrl keys if you need to!
avast! Free Antivirus 8 then scans the item(s) and if everything is okay, you will see a green "No threat found" message. Click Close.
In case infected items were detected, you will see a red "Threat detected" message after the scan is complete. Click Show Results button.
An avast! Scan Results window opens with a list of all detected items. The default action is "Move to Chest" and this suits fine. Click the Apply button.
Please note that sometimes avast! real-time protection engine has already removed the infection(s) and the Apply button is grayed out. In case you are unable to click the button, don't worry - the threats have already been removed.
Cleaning might take up to several minutes. For each threat removed, "Action successful" message should appear in Result column.
As avast! Free Antivirus does not support removing individual files from every kind of archives, you might sometimes encounter an error named "the operation is not supported for this type of archive". In such case ignore the error and either delete the whole archive file manually or run a Malwarebytes' Anti-Malware scan on the file immediately after closing the avast! Scan Results window.
Click Close button to finish.
If you want to run a more thorough scan, open avast! Free Antivirus 8 by clicking its orange ball-shaped icon in Taskbar Notification area.
Click Security tab on the top row, expand Antivirus tab and then Scan Now tab. Find the scan you want to perform. Click Start button to the right of the scan.
The scan starts. As checking for viruses and malware can slow your computer down, you can click Pause if you really need to. To continue scanning, click Resume button. The Stop button is only for emergencies.
The number of threats detected is displayed on the Infected files line.
If a scan finishes without detections, a green "No threat found" message appears. You can click OK button then and close avast! Free Antivirus main window using keyboard shortcut Alt+F4.
If some malware was detected, you will see a red "Threat detected" message after the scan is complete. Click Show Results button.
avast! Scan Results window opens with default action for detected items set to "Move to Chest". This is fine, click Apply.
"Action successful" is displayed in the Result column for each removed threat. Click Close.
There might be cases when a virus-infected file has already been deleted by avast! File Scanner. You will see an error message "The system cannot find the file specified (2)" then. This is not a problem, as the infected file has already been removed or moved to Virus Chest.
If avast! Free Antivirus 8 has also detected a virus in operating memory, or some of the detected threats require a full scan during boot-time, it will display the following information message and offers to perform a boot-time scan. Always click Yes here and, otherwise your computer might stay infected! This will restart your computer and trigger a lengthy boot-time scan to remove the infection.
It is strongly recommended to stand by during a boot-time scan, because a manual action is required if a threat is detected. In such cases, always use option number 4 to move infected files to Chest.
Read the avast! Free Antivirus boot-time scan article for more information about boot-time scanning and errors that might occur.