Avast Free Antivirus on-demand scan
Despite Avast Free Antivirus 2015 weekly 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.
New to Avast 2015 is the Smart scan feature that checks for viruses, outdated software and network security weaknesses.
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.
There are times when some malware disables or impairs your security software. In such cases, use free RKill that detects and stops (but does not remove!) active rootkits, trojans, worms, etc. After the quick (up to 5 minutes only!) scan completes, avast! Free Antivirus should be able to run again and they can probably remove the malware.
You might also want to double-check your PC with Malwarebytes Anti-Malware.
To scan just one file or folder (aka directory) with Avast, right-click the item in Windows/File Explorer and select Scan <item name>. You can also select multiple items using Shift (consecutive items) or Ctrl (non-consecutive items) keys if you need to.
Avast Free Antivirus 2015 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 Fix automatically - this is the best one, as it lets Avast choose the best possible solution.
If Result column is empty, click Apply. Then verify that "Action successful" is displayed for all listed items. If not, change the action for failed items to Move to Chest and hit Apply again.
Sometimes Avast real-time protection engine has already removed the infection(s) and the Apply button is grayed out. The same situation happens if you configured Avast to automatically remove all threats.
In case you are unable to click the button and "Action successful" is displayed, don't worry - the threats have already been removed. Just click Close.
As Avast Free Antivirus does not support removing individual files from all 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 2015 by clicking its orange ball-shaped icon in Taskbar Notification area.
Click Scan tab from the left and click Scan for viruses.
Select a suitable scan from the drop-down menu on the right and then click Start.
While the scan is running, 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. As long as no items have been detected, the progress circle is in blue.
If malware has been detected, the progress circle turns red, and Infected files shows how many threats have been found.
If a scan finishes without detections, a green "No threat found" message appears. You can close Avast Free Antivirus main window by clicking the X button on top right, or by using keyboard shortcut Alt+F4.
In case some malware was detected, you will see a red "Threat detected!" message instead. Click Show Results.
avast! Scan Results window opens with default action for detected items set to "Fix automatically". This means that Avast works out the best solution for each threat found.
Click Apply. Please note that if you've configured the scan to perform actions automatically, the actions have been carried out already. Just verify that "Action successful" is displayed in Results column and click Close.
There might be cases when a virus-infected file has already been deleted by Avast real-time protection engine: you will see an error message "The system cannot find the file specified (2)" for such items. This is not a problem, as the infected file has already been deleted or moved to Virus Chest.
If Avast Free Antivirus 2015 has not been able to remove a virus from operating memory (Random Access Memory, aka RAM), or some of the detected threats require a full scan during boot-time, the following information message is displayed.
In such cases, it is strongly recommended to use RKill and Malwarebytes Anti-Malware before clicking Yes. Inexperienced users can make Windows unbootable or unstable with boot-time scanning if they choose to delete or move essential system files. The two aforementioned programs are safer bets and you might get rid of the infection even without running the lengthy boot scan.
Read the Avast Free Antivirus boot-time scan article for more information about boot-time scanning and suggested actions for infected files.
If the same malware still reappears, use RKill for detecting and stopping active malware services and processes (the scan takes only about 5 minutes!). Then use Malwarebytes Anti-Malware or ComboFix to get rid of the infection.
Smart scan is a new feature to Avast 2015: it checks for viruses, browser toolbars, outdated software and home network weaknesses. By default, the virus/malware scanning part checks for rootkits and tests auto-start programs only. While this makes the scan much quicker, it will probably miss most malware.
In addition, paid GrimeFighter is also run by default: it does detect unneeded temporary files, registry problems and other stuff that needs removing, but it will not display any useful details about detected items, and it will not remove a thing in free version of Avast. This is why you need to turn it off and use free CCleaner instead.
You can also put Avast Free Antivirus on a diet by removing the features you do not need.
To make Smart scan more useful, open Avast main window and click Settings on the left. Scroll down the General tab and click to expand Smart scan section.
First, set GrimeFighter to Off position, and then make sure that all other items have been turned On. If you're using Secunia PSI or other automatic software updater, you might want to disable the Scan for outdated software item, too.
Then click Customize to the right of Scan for viruses.
Locate the Scan Areas section in avast! Scan Settings window, Scan tab. Add Modules loaded in memory as the third area to scan. Then add another one and click Browse.
If you are the only active user of this device, tick the check box left of your (user) name. This means that Smart scan will run a virus check inside your profile folder.
In case you have multiple users on the PC, expand (My) Computer, and then expand the drive where Windows is installed (most probably the drive with letter C:). In Windows Vista and newer, tick the Users folder; in Windows XP the folder is named Documents and Settings. Smart scan will then check all users' profiles.
Click OK again to close avast! Scan Settings window. You just made Smart scan much smarter.
To launch the scan, open Scan tab in Avast main window and click Smart scan.
If you've never run this type of scan, it launches right away without any confirmation. If you've used this scan before, there is a Rescan link available below latest results.
You cannot pause Smart scan for some strange reason, but the Stop button is still there on top right.
If everything checks out fine, a green check mark is displayed to the left of "Smart Scan completed" message. You will see the same info the next time you click Smart scan: to update results, click Rescan below results.
In case issues were found, you need to click the Resolve All button.
Avast Smart scan displays the number of detected virus and malware threats, click Resolve All again.
After cleaning viruses and malware, the result should read "All threats have been removed". Click Next.
In case Avast fails to resolve all threats, run RKill and Malwarebytes Anti-Malware after resolving other issues.
If out-of-date programs were detected, Avast offers to manually update these. Automatic updating is available in paid versions only. Please note that free Secunia PSI can do the same job automatically.
Click Update for every item in the list.
avast! Software Updater window opens, and the update is downloaded and installed. Click Close after the process is complete.
Click Next after updating all outdated programs.
If some potentially unwanted or malicious toolbars were found hogging your web browser(s), click the blue Completely remove button.
The list of detected toolbars and toolbar protectors appears again. As Avast interface just loves clicking, hit the Remove all button now.
In case a toolbar has set its own home page and/or search provider in a browser, Avast offers some default and safe choices. While Yahoo! is the recommended option here, I personally prefer Google (or the choice not offered here: DuckDuckGo).
Click Complete Free Cleanup.
I really do not know why, but Avast Smart scan keeps confirming the same action all over again. Yes, we already told Avast to remove the bad add-ons, but hey - here's another lovely Continue button to click.
Finally the misbehaving extensions will be removed, it will probably take less time than clicking the confirmation buttons. Click Close and then click Next in the Avast Smart scan results.
In case Smart scan detected some problems with your home network, the list appears next. In this case, the router is accessible from the Internet; other possible problems include weak or default router and Wi-Fi passwords, and network/router settings that make the devices easy to attack.
Clicking Go to the router settings opens the default web browser and navigates to router console. To see instructions for resolving the problems, click More info on bottom left: Avast help includes tutorials for most common routers.
Click Next after resolving the problems.
And finally, here's an example of the paid GrimeFighter scan. There's nothing you can do about the detected items, because the feature works only in paid versions of Avast.
Click Settings to exclude GrimeFighter from future Smart scans. Free CCleaner does the job of removing temporary and duplicate files, cleaning the Registry, and even more.
In GrimeFighter settings window, clear the Always test this computer for Grime check box and click OK.
You should also disable GrimeFighter in Avast Smart scan settings.
Click Skip in Smart scan results.
Please note that you can completely remove unnecessary features of Avast by following the Put avast! Free Antivirus on a diet tutorial on my sister site, www.winhelp.info.