Why Is Avast Unable To Scan Some Files? [Avast Scanning Guide]

Avast is a free anti-virus that has a paid tier. For most cases, there is no reason to buy it as the free version provides everything a home user would need. There are some cases, however, in which Avast is unable to scan files. So, you may be asking yourself, ‘Why Is Avast Unable To Scan Some Files?’

There are several reasons that a file would be unable to be scanned by Avast Antivirus. It could be something as simple as a password-protected file. If a file or an archive of files is password, Avast will not be able to scan it. It could also be something more complicated such as a corrupted file or failing hard drive. 

Just because Avast cannot scan a file doesn’t mean that the file is a threat. In this article, we will take you though all the possible cases in which Avast wouldn’t be able to scan a file. We will also explain some steps that can help you scan files that you may have been unable to scan before.

Why Is Avast Unable To Scan Some Files?

If Avast is unable to scan some files on the computer, it could mean several things ranging from benign to serious. Usually, though, being unable to scan a file is not an indicator of having a virus infection. It could be an internal system issue like a bad hard drive or a software issue like file corruption.

If you want to see Avast’s explanation for why a specific file could not be scanned, just follow these steps:

Step 1: Perform a Scan

Step 2: Click where it says ‘some files could not be scanned.’

Step 3: After that, click ‘Detailed Report.’

Step 4: View the log to see why some files could not be scanned by Avast.

This will give you much more detailed information than a general blog post like this can. After you look at the report, if you are curious as to the nature of each item on the list, all you have to do is Google it.

There really is a shocking amount of information out there on the internet. If you enter error codes, error messages, or just about anything else directly into Google, changes are you are going to get a page full of useful results.

Its as simple as this: Files that can’t be scanned are files for one reason or another cannot be scanned. It’s not an indication that those files are suspicious or infected; it simply means that these files need another element before they can actually be opened and examined by Avast Antivirus.

A lot of programs password protect or otherwise encrypt their files for legitimate purposes. Remember, Avast doesn’t know your passwords or any of the passwords for any of the files on your system. So, it won’t be able to scan these files. 

Avast Smart Scan Stuck

Sometimes it may appear as though Avast is having a problem with scanning files, but its actually just getting stuck in general. If this is happening to your installation of Avast, you should follow these guidelines to fix the issue.

Step 1: First, open your computer’s Control Panel

Step 2: Next, click the Programs & Features

Step 3: Click Add or Remove programs and locate Avast in the list

Step 4: Click Repair 

Step 5: Wait until the Avast application is repair completes

Step 6: Check to see if the Avast scan runs without issues

Avast Mobile Scan Failed

Sometimes, the mobile version of Avast can experience general issues when scanning files. You can clear Avast cache to see if that fixes the problem. To do this, just follow the steps below.

Step 1: Open the Settings application on your mobile device.

Step 2: Tap Apps and then locate the Avast application.

Step 3: Tap ‘Clear Cache’ and ‘Force Close’

Step 4: Launch Avast and try to scan again to see if the issue is resolved

If the Avast mobile scan still wont work after trying this, try to uninstall and reinstall the application from Google Play. This can reset things and get Avast mobile working again.

How Can I Scan More Files With Avast 

In Avast, you can perform more than one type of scan. In fact, there are all kinds of settings in the popular antivirus program that will allow to you scan a whole lot more files than it usually does. Below are some of the scan options and what they do:

  • Scan type: Selects the type of scan you want to perform
  • Sensitivity (Medium by default): The higher the sensitivity, the higher the protection and the more files Avast will scan. A more sensitive scan will also take more time
  • Test whole files: Check this to let Avast to scan complete files rather than only the parts typically associated with malicious code
  • Scan areas: You can scan a lot more files if you tell Avast to look for threats on all available Hard Disks rather than only your system boot drive.
  • File Types: Here, you can tell Avast white types of files you want it to scan for or simply ignore. This settings make a major impact on the number of files that Avast scans in total

There Are Special Cases Where Avast Wont Scan Some Files

Although there are several reasons why a scan may be unable to complete, here are some of the most common ones:

  • Archive or file is corrupted: Indicates that the file may be corrupt because it was only partially downloaded or saved to your hard drive, or that it is a special type of archive.
  • The process cannot access the file because of another process: Indicates that another process or program was accessing the file during the scan.
  • The file is a decompression bomb: Indicates that the file was too large to be decompressed for malware analysis. Decompression of large files generates vast amounts of data which can cause your system to be unstable or cause it to crash.

As you can see, there are several totally normal cases in which Avast won’t be able to scan some files.


So yes, sometimes Avast wont scan all your files, but this doesn’t mean that there is a virus infection on your computer.

It also doesn’t mean that there is a problem with your system or antivirus, although in some cases, being unable to scan files that are normally scannable could be an indicator of something wrong with your system.

We hope that in your investigation, you found out that it was something as simple as a harmless system file that looked suspicious or a password-protected file. If you have instead determined that being unable to scan a file in Avast is a sign of a more serious concern, then you should definitely have it looked at.

Either way, we are glad that you took the time to read  this article and we hope it helped you in your quest to find out why Avast why scan some files. The more you know about how something works, the more information of a decision you will be able to make when things go wrong.