If you Think you have been infected with malware, the best thing to do is to avoid panic. In many cases, you can recover your PC and remove the infection using the Microsoft Windows Defender tool or using third-party antivirus software such as Avast to look for and remove the infection.
Even stubborn malware infections it can be removed using these tools, but you may need to do a boot-level scan using portable software on a USB drive, especially if Windows is not safe to run with malware. To run an offline virus scan using Microsoft Defender or a third-party antivirus solution, you must follow these steps.
Running an offline virus scan using Microsoft Defender on Windows 10
If Windows is still running and the malware infection is not as severe, you may be able to use Microsoft Defender to run a boot antivirus without using the portable (and earlier) Windows Defender offline tool.
This option is only recommended, however, if Windows can still run and remain isolated from other PCs on your network.
For example, if you plan to use this method, make sure your PC is disconnected from your local network. This will prevent any malicious software from spreading to other computers before the infection can be removed. You may want to restart Windows in safe mode before continuing.
- To get started, right-click on the Start menu and select Configuration.
- A la Window settings menu, select Update and security > Windows security > Protection against viruses and threats.
- A la Protection against viruses and threats menu, select Scanning options.
- Select Microsoft Defender offline scanning in the list provided and select Scan now to schedule the scan.
- Windows will confirm that your computer needs to be restarted. Close unsaved applications at this time and select Scan to restart your computer and start the boot antivirus scan using Microsoft Defender.
- After a few moments, Windows will restart and boot from the Microsoft Defender boot scan menu. Microsoft Defender will automatically start scanning your PC for malware; allow this process to fully scan your PC. If it detects malware, follow the additional on-screen instructions to confirm how you want to correct, delete, or quarantine infected files.
Once the offline virus scan is complete, your PC will restart again in Windows. All malware will be removed or quarantined according to your previous actions. At this point, the malware infection should be resolved, but you may need to follow additional steps to do so. repair or restore the Windows installation (depending on the damage).
Using the old Windows Defender tool offline to look for malware (earlier versions of Windows)
While Windows 10 allows you to scan for offline viruses with Microsoft Defender without additional tools or hardware, you can also use the older version Windows Defender Offline tool on a portable USB or DVD drive to perform a boot-level scan when Windows can’t (or can’t).
Although this portable version of Defender was originally made for Windows 7 and 8.1, it can still be used to search for malware. some PC with Windows 10, depending on the version. However, the tool itself is out of date (although virus definitions are up to date) and will not work with newer versions of Windows.
For this reason, this tool should only be used on older computers running an earlier version of Windows 10 (or an earlier version of Windows). If that doesn’t work, you may need to use a third-party antivirus as an alternative or schedule a Microsoft Defender offline scan in safe mode using the steps above.
Creation of the Windows Defender Offline USB or DVD Media tool
- If you want to try this method, you will have to do it download the 64-bit version of Windows Defender Offline from the Microsoft website from an uninfected Windows PC. Once the file is downloaded, run the tool and select it Next.
- In the next step, confirm that you accept the license agreement by selecting the file I accept button.
- You will need to select where you want to install Windows Defender offline. Select the appropriate option (such as On a USB flash drive that is not password protected) and select Next to be confirmed.
- If you are using the USB flash drive method and you have more than one USB device connected, select the device you want to use based on the letter of the assigned drive using the drop-down menu, then select the Next option.
- The tool will format and reflect the USB drive you selected. Be sure to back up all previously saved files to your device, then select Next to continue.
- The Windows Defender Offline Creator tool will download the files needed to flash your USB drive or DVD (including updated virus definitions). Once the process is complete, you will need to restart your PC.
Scan your PC using USB Defender or Windows Defender offline
- When you restart your computer, you will need to configure the BIOS or UEFI boot loader to boot from your USB drive, rather than from your Windows system drive. You will usually need to select a keyboard key such as F1, F12, or FROM to start this menu and change this setting: See your PC’s user manual for additional information on how to do this, as the steps vary, depending on the manufacturer.
- Once you have changed the boot order, a minimal, isolated Windows environment running Windows Defender will start. If your version of Windows 10 supports this tool, browsing options will be available to you. Otherwise, a 0x8004cc01 an error will appear and you will have to try an alternative method.
- However, if the Windows Defender tool can run on your version of Windows 10, follow the on-screen instructions to scan your PC and treat the infected files. Once the process is complete, your PC will restart and the malicious software should be removed. Be sure to remove the USB drive or DVD right now and restore the correct boot order to the BIOS or UEFI settings to make sure Windows will boot properly afterwards.
Running an offline virus scan using third-party antivirus software
While Microsoft Defender is a built-in antivirus suitable for Windows 10 users, you can also use third-party antivirus tools to scan your PC for offline viruses. All major antivirus vendors support this feature, including the free-to-use Antivirus avast, although alternatives to Avast they are available and are perfectly adequate.
- To get started, you will need to download and install Avast on an uninfected PC (or, if not possible, on your infected PC if your PC is still booting). Once installed, open the Avast user interface by selecting the Avast icon on the taskbar. From the Avast menu, select Protection > Virus analysis.
- A la Virus analysis , select the menu Rescue disk option.
- If you prefer to create a rescue disc using a CD or DVD, select Create a CD. Otherwise, connect a portable USB flash drive and select Create USB However.
- Avast will need to format and reactivate the drive with the correct files. Back up all the files you want to save from the drive, then select Yes, it overwrites to continue.
- Take some time to complete the process. Once Avast has created the rescue disk, safely remove it from the PC you are using and connect it to your infected PC. If you used your infected PC to create the Avast rescue disk, restart your PC right now.
- Before booting to the Avast rescue disk, you must change the boot order in the BIOS or UEFI settings by selecting F1, F12, DEL, or a similar key (depending on your hardware) to boot into this menu. Be sure to prioritize the DVD or USB flash drive you created and restart your PC.
- Once rebooted, select any key on the keyboard to boot to the Avast rescue disk. Select with the mouse AvastPE Antivirus.
- A la Avast Antivirus from the options menu below, you can scan all connected drives or scan only certain folders / files. Select the preferred option, then select Next.
- Avast will begin scanning your drives for malware. Follow the additional on-screen instructions to confirm how you want to manage infected files, such as fixing, quarantining, or deleting them.
When the process is complete, exit the Avast rescue disk software, restart the PC, and remove the rescue disk to boot into Windows. You may need to repeat the above steps to restore the original boot order in the BIOS or UEFI setup menu before you can do this.
Keep Windows 10 free of malware
Whether you’re using Microsoft Defender or a third-party antivirus like Avast, you should be able to use these tools to free your PC from harmful malware infection. However, if you are still having problems, you may need to think about cleaning your hard drive and reinstalling Windows to restart without infected files.
While we’ve shown you how to use Avast to remove malware, it’s not the only third-party option available. You can easily uninstall Avast on Windows and try another solution like Webroot. However, if the rest fails, be sure to use Microsoft Defender to do so Quickly Remove Malicious Software from your Windows PC.