if you think you have been infected with malware, the best thing to do is to avoid panicking the patient. In many cases, you can restore your PC and remove the infection by using Windows’ own Microsoft Defender tool or by using third-party antivirus software like Avast to scan and remove the infection.
Even stubborn malware infection can be removed with these tools, but you may need to run a boot-level scan with portable software on the USB drive, especially if Windows is not safe to run with malware. To scan for viruses offline using Microsoft Defender or a third-party antivirus solution, you need to follow these steps.
Run Offline Virus Scan with Microsoft Defender on Windows 10
If Windows is still running and the malware infection is not severe, you can use Microsoft Defender to run a bootable antivirus scan without using the portable Windows Defender Offline tool (and older).
However, this option is only recommended if Windows can still run and remains isolated from other PCs on your network.
For example, if you are going to use this method, make sure your PC is disconnected from your local network. This will prevent any potentially harmful software from spreading to other PCs before you can remove the infection. You may want to restart Windows in Safe Mode before continuing.
- To get started, right-click the Start menu and select Setting.
- inside Window settings menu, select Update & Security > Windows Security > Protection from threats and viruses.
- inside Protection from threats and viruses menu, select Scan option.
- Option Scan Microsoft Defender Offline from the list provided, then select Scan now to schedule a scan.
- Windows will confirm that your PC will need to restart. Close any unsaved apps at this point, then select To scan to restart your PC and start a bootable antivirus scan with Microsoft Defender.
- After a while, Windows will restart and boot into the Microsoft Defender boot scan menu. Microsoft Defender will automatically start scanning for malware on your PC — allowing it to scan your entire PC. If it detects any malware, follow any additional on-screen instructions to confirm how you want to fix, delete, or quarantine any infected files.
Once the offline virus scan is complete, your PC will reboot into Windows. Any malware will be removed or quarantined based on your actions above. At this point, the malware infection should be resolved, but you may need to follow additional steps to repair or restore your Windows installation (depending on damage).
Use Older Windows Defender Offline Tool to Scan for Malware (Older Windows Versions)
While Windows 10 allows you to conduct offline virus scans with Microsoft Defender without any additional tools or hardware, you can also use an older version Windows Defender Offline tool on a removable USB drive or DVD to perform a boot-level scan when Windows cannot (or should not) start.
Although this Portable version of Defender was originally created for Windows 7 and 8.1, it can still be used to scan for malware on some PC running Windows 10, depending on version. However, the tool itself is outdated (although virus definitions have been updated) and will not work with newer versions of Windows.
For this reason, this tool should only be used on older PCs running an earlier version of Windows 10 (or an earlier version of Windows). If it doesn’t work, you may need to use an alternative third-party antivirus or schedule a Microsoft Defender Offline scan in Safe Mode using the steps above instead.
Create Windows Defender USB or DVD Media Offline Tool
- If you want to try this method, you need to download 64-bit version of Windows Defender Offline from Microsoft’s website from an uninfected Windows PC. After the file is downloaded, run the tool and select Next.
- At the next stage, confirm that you accept the license agreement by selecting I agree button.
- You will need to choose where you want to install Windows Defender Offline. Select the appropriate option (such as On a USB flash drive that is not password protected) then select Next confirm.
- If you are using the USB flash drive method and you have multiple USB devices connected, select the device you want to use based on the specified drive letter using the drop-down menu, then select Next right to buy.
- The tool will format and recombine the USB drive you selected. Be sure to back up any previously saved files to the device first, then select Next to continue.
- The Windows Defender Offline Creation Tool will download the files needed to flash your USB drive or DVD (including up-to-date virus definitions). Once the process is complete, you will need to restart your PC.
Scan your PC with Windows Defender Offline USB or DVD Media
- When restarting your PC, you’ll need to first configure the BIOS or UEFI bootloader to boot from your USB drive, rather than from your Windows system drive. Usually, you’ll need to select a keyboard key, such as F1, F12, or DEL to boot into this menu and change these settings — refer to your PC’s manual for more information on how to do this, as the steps vary, depending on the manufacturer.
- Once you’ve changed your boot order, a minimal and isolated Windows environment running Windows Defender will start. If your version of Windows 10 supports this tool, the scanning options will be available to you. Otherwise, one 0x8004cc01 error will appear and you need to try an alternative method.
- However, if the Windows Defender tool can run on your version of Windows 10, follow the onscreen instructions to scan your PC and deal with any infected files. Once the process is finished, your PC will reboot and the malware will be removed. Make sure to remove your USB drive or DVD at this point and restore the correct boot order in your BIOS or UEFI settings to ensure that Windows will boot correctly afterwards.
Run an offline virus scan with third-party antivirus software
While Microsoft Defender is the right built-in antivirus for Windows 10 users, you can also use third-party antivirus tools to perform an offline virus scan of your PC. mine. All major antivirus software vendors support this feature, including Avast Antivirus which is free to use, although alternatives to Avast available and perfectly matched.
- To get started, you need to download and install Avast on an uninfected PC (or if that’s not possible, on an infected PC if your PC still boots). Once installed, open the Avast user interface by selecting the Avast icon on the taskbar. From the Avast menu, select Protection > Virus scan.
- inside Virus scan menu, select Rescue disc right to buy.
- If you want to create a rescue disc using a CD or DVD, select Create a CD. If not, connect a portable USB flash drive and select Create USB instead of.
- Avast will need to format and re-decrypt your drive with the correct files. First back up any files you want to save from the drive, then select Yes, override to continue.
- Allow some time for the process to complete. After Avast has created your 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 an Avast rescue disc, restart your PC at this point.
- Before booting to the Avast rescue disk, you need to change the boot order in your BIOS or UEFI settings by selecting F1, F12, DEL, or similar key (depending on your hardware) to boot into this menu. Make sure to prioritize the DVD or USB flash drive you created, then restart your PC.
- After rebooting, select any key on the keyboard to boot into the Avast rescue disk. Using YOUR MOUSE, select AvastPE Antivirus.
- inside Avast Antivirus the options menu that appears next, you can choose to scan all connected drives or scan only certain folders/files. Choose your preferred option, then select Next.
- Avast will start scanning your drive for malware. Follow any additional on-screen instructions to confirm how you want to handle the infected files, such as fixing, quarantining, or deleting them.
When the process is complete, exit the Avast rescue disk software, restart your PC, and remove the rescue disk to boot into Windows. However, you may need to repeat the steps above to restore the original boot order in the BIOS or UEFI settings menu before you can do this.
Keep Windows 10 free of malware
Whether you’re using Microsoft Defender or third-party antivirus software like Avast, you’ll be able to use these tools to free your PC from harmful malware infections. However, if you are still having problems, you may need to think about wiping the hard drive and reinstall Windows to start over without any infected files.
While we’ve covered how to use Avast to remove malware, it’s not the only third-party option available. You can go crazy uninstall Avast on Windows and try another solution like Webroot instead. However, if all else fails, don’t forget to use Microsoft Defender to quickly remove malware from your Windows PC.