14 Free On-Demand Virus Scanners

SUPERAntiSpyware Free Edition

SUPERAntiSpyware Free Edition detects spyware in the registry and file system, as well as those running in memory. Some advanced settings are available, like scanning just cookies and including/excluding particular folders from a scan. You can also use the free version to scan only the files running in memory, called a Critical Point Scan, which is useful if you think a piece of malware is currently running. This also gives you a quick view of potentially unwanted programs installed on your PC, and a dead-simple method to remove them.

There's a section of the program to show the applications that start up with Windows, as well as SUPERDelete, which lets you remove files that won't properly delete, and the ability to only scan files that were modified within a certain period of time.

Other useful tools and features are included as well, like a startup manager, ignoring large files, ignoring System Restore files, and scanning inside ZIP archives.

Something you might find annoying is that some of the options are only available in the paid version, like email alerts and scheduled scans, but it's not easily decipherable as to which features are or aren't. Clicking these areas will show an ad to download the full version.

You can use this program in Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, Windows 8/8.1, Windows Server 2012, Windows 10, and Windows 11.

Malwarebytes

Malwarebytes is one of the most popular free virus scanners. In our experience, it has found more malicious files than any other virus scanner we've used.

You can perform a threat scan to detect infections in locations malware normally hides, such as in the memory, registry, and file system. A custom scan can be launched as well, which scans any or all hard drives and folders with the option to include memory objects, startup items, the registry, archives, and rootkits.

Malwarebytes can also detect potentially unwanted programs (PUP) and modifications (PUM), start scans from the context menu in File Explorer, and exclude files/folders from scans.

We also like that it clearly shows which features are premium before you try to use them (many software programs don't do this). The free version lets you trial the paid features if you wish to use them.

This app lets you run virus scans for free on Windows 11, 10, 8, and 7, as well as macOS 10.12 and higher.

Emsisoft Emergency Kit

Emsisoft Emergency Kit (EEK) scans for viruses, Trojans, spyware, rootkits, adware, PUPs, worms, etc., similar to the programs in this list. You can exclude particular files and folders from a scan if you need to.

There aren't any ads, so you don't have to deal with a cluttered interface, and it's easy to understand where you need to go to edit settings, access quarantined files, etc.

EEK runs on Windows 11, Windows 10, and Windows Server 2016 and newer.

Stinger

From Trellix, Stinger (formerly called McAfee Stinger) is a free, portable on-demand virus scanner with scan targets that include running processes, boot sectors, registry keys, and rootkits.

You can create a custom scan to just search in particular directories and/or hard drives, or a complete scan that searches through everything. You can see the long list of threats it can find from the included Threat List.

Stinger can be set up to repair, report, rename, or remove malware. If you know the hash of files you don't want to be scanned, it lets you build a list of them so that the program skips over them.

The download size is around 50 MB and doesn't require installation, enabling Stinger to run from a flash drive or external hard drive. You need Windows 7 or newer.

Microsoft Safety Scanner

Microsoft Safety Scanner (also called MSERT) is a free on-demand portable scanner from Microsoft that checks for and removes spyware and similar malicious files.

You can run a quick scan to check only critical areas where viruses may be resting, a full scan to check every file and folder on your PC, or a custom scan to couple a quick scan with a scan of any other folder of your choosing.

Microsoft's free virus scanner deletes malicious software from Windows 11, Windows 10, Windows 8/8.1, Windows 7, and various Windows Server editions.

Dr.Web CureIt!

Dr.Web CureIt! is the same software as what's in the bootable Dr.Web LiveDisk program, but works within Windows instead of from a disc. It's a completely portable virus scanner, making it a great way to provide free on-demand virus scanning capabilities without having to install something.

You can scan boot sectors, the memory, the Windows folder, temporary files, system restore points, rootkits, or custom files and folders. Useful settings let you toggle tasks like to interrupt scanning when you switch to battery power (for laptops) or to automatically apply actions to threats.

eScanAV Anti-Virus Toolkit (MWAV)

eScanAV Anti-Virus Toolkit is a completely free portable virus scanner for Windows.

It checks for spyware, adware, keyloggers, and similar potentially malicious items running in the system memory. It can also scan an individual folder or whole disk drive. You have the option to just scan without repairing any files and to include scanning archive files.

Updates can be performed because the program installs itself to a temporary location while you use it. However, this is also a downfall because it means you have to run the setup file again if you wish to use the program in the future, given that all the files were unloaded to a seemingly undisclosed location on your computer.

Something else a bit bothersome about this program is that it displays an advertisement every time you close it.

Norton Power Eraser

Norton Power Eraser is a portable on-demand free virus scanner that's just around 20 MB in size.

There are a few scan options on the start page, so you can full a full system scan, a specific scan against certain files or a particular folder, or an 'unwanted application scan' to identify apps Norton suggests you remove. Rootkit scanning is supported, too, but you have to enable it in the settings.

This option works on Windows 7 and newer.

Sophos Scan & Clean

Sophos Scan & Clean is an on-demand free virus scanning tool for Windows that scans for viruses in the file system and memory. Every time the program is started, it automatically begins an update to be sure its definitions are current, which is nice.

There are some advanced options, but they're not your usual ones. These let you automatically upload suspicious files to the Scan Cloud, compress files before upload, scan for tracking cookies, and auto-create a restore point before removing files.

There's not a pause button in this scanner, but the scan is thorough, and the program lets you remove any viruses it finds when it's finished.

It has to be installed to be used, but it's a small setup file. It works with Windows 7 and newer.

HouseCall

Trend Micro HouseCall is a portable, lightweight on-demand virus scanner for Windows. It finds and eliminates Trojans, viruses, worms, and spyware.

The program automatically updates when you open it to stay current with recent releases and definition updates.

You can run a quick scan, full scan, or custom scan to select specific folders and drives.

Trend Micro HouseCall is completely portable and just a few megabytes in size, making it ideal to place on a portable drive.

F-Secure Online Scanner

F-Secure Online Scanner is another decent free virus scanner that doesn't scan every location on a PC but instead looks through folders where viruses are normally found.

There are absolutely zero custom settings, so it's a good option if you're not familiar with how these apps work and you just want a simple way to run a free scan. If it finds a virus, it's removed without question and doesn't prompt you to decide to keep it.

ESET Online Scanner

ESET sells home and business security software, but they also offer this free scanner that locates and removes viruses, Trojans, spyware, phishing, and other internet threats.

The scan types include full, quick, or custom, the latter of which lets you check for threats on a drive, in a folder, or in specific files.

When a scan is finished, the results can be sent to your email. This is a great idea if an IT professional requests the scan, so they can review the results.

Panda Cloud Cleaner

Panda Cloud Cleaner scans the registry, system memory, and other common locations where malware could be hiding. You can also scan individual files and folders, shut down all running processes, unlock files, and submit suspicious files to Panda for analysis.

The download is relatively small but you do have to install it. It runs on Windows 11 through Windows XP

ClamWin Free Antivirus

ClamWin Free Antivirus is a free on-demand virus scanner that can be installed on Windows or launched from a removable USB drive.

It can scan just the system memory to find viruses that are currently running, or scan the entire file system (or specific files/folders) for malicious items.

Scheduled scans are supported as well as Windows Shell integration, email alerts, file exclusions, and Microsoft Outlook email scanning.

Below is the download link for the installable version. ClamWin Portable is available through PortableApps.com.