Command Prompt window showing the command to navigate to the Avast installation directory

How to Run an Avast Boot-Time Scan to Remove Stubborn Malware

admin February 21, 2025No Comments

If malware is preventing Avast Antivirus from running properly, especially a Boot-Time Scan from within the regular Windows environment, you can still initiate a scan by using Windows Safe Mode and the Command Prompt. This method allows you to schedule and execute a Boot-Time Scan outside of the normal operating system, increasing the chances of removing persistent threats.

Here’s how to schedule and run an Avast Boot-Time Scan when you can’t do it from the usual interface:

Step-by-Step Guide to Scheduling an Avast Boot-Time Scan via Command Prompt

Restart Your Computer into Safe Mode with Command Prompt. The process varies slightly depending on your Windows version. Generally, you’ll need to restart your computer and repeatedly press the F8 key or Shift + F8 as it boots up. This should bring you to the Advanced Boot Options menu where you can select Safe Mode with Command Prompt. If this method doesn’t work, consult Microsoft’s official support or your computer manufacturer’s guide for specific instructions on booting into Safe Mode with Command Prompt for your Windows version.
Navigate to the Avast Installation Directory in Command Prompt. Once you are in the Command Prompt environment, you need to tell the command line to access the Avast installation folder. Type the following command, assuming Avast is installed in the default location, and press Enter:
```
CD C:Program FilesAvast SoftwareAvast
```
If you installed Avast in a different location, you’ll need to use that path instead. If you’re unsure, try the default path first, and if it doesn’t work, you may need to explore your file system to find the correct directory.
Schedule the Boot-Time Scan Command. Now that you are in the Avast directory, you can schedule the Boot-Time Scan. Type the following command and press Enter:
```
sched /A:*
```
or
```
sched.exe /A:*
```
This command tells Avast to schedule a Boot-Time Scan to run on all local drives the next time your computer starts up.

For more advanced options and to see all available command-line parameters for the scheduler, you can simply type sched or sched.exe and press Enter. This will display a list of commands you can use.
Reboot Your System to Initiate the Boot-Time Scan. After you have successfully scheduled the scan, you need to restart your computer for the Boot-Time Scan to begin. In the Command Prompt, type the following command and press Enter:
```
shutdown /r
```
This command will restart your computer, and the Boot-Time Scan will automatically commence before Windows fully loads.
Observe and Manage the Boot-Time Scan Process. Once your computer restarts, you will see a dedicated Avast Boot-Time Scan screen appear. This indicates that the scan is in progress, running before the operating system fully boots.

During the scan, Avast will examine your system for malware. If any threats are detected, you will be prompted to choose an action, such as delete, repair, or move to quarantine. Follow the on-screen instructions to resolve any detected issues.

The duration of the scan depends on your system’s speed and the size of your hard drives. It can take anywhere from a few minutes to a longer period.

If you wish to skip the Boot-Time Scan for any reason, you can press the Esc key on your keyboard while the scan is in progress. Windows will then continue to boot normally.

Once the scan is complete or skipped, your computer will finish booting into Windows. You can then check Avast’s scan logs for details of the Boot-Time Scan results.

This method provides a way to effectively use Avast’s Boot-Time Scan feature even when malware interferes with your system’s normal operation, ensuring a deeper level of threat detection and removal.

Applies to: