Virus programs you don’t have to install
Run it from a flash drive or any folder
A portable antivirus program can be used without installing it to your computer. They’re a great “second look” next to a standard, installable virus scanner, and are especially helpful if you need to scan viruses from a flash drive.
Another reason to use one is if you need to check for a threat right now but you don’t have a full-fledged virus scanner installed. Most of the virus scanner freeware below can be downloaded and start a scan in just a couple minutes.
This is an alphabetized, master list of virus scanner tools you don’t have to install, updated for 2020, that you can get absolutely free.
Note: Some of these virus checkers need to be decompressed, something you can do in Windows or with a program like 7-Zip.
List of Portable Virus Scanners
A single Start button without any custom settings or additional options. Scan, choose what to delete, and hit Clean infections.
Run a regular scan or a full scan, and wait for the results. There aren’t any custom options, like for scanning certain folders/files or particular hard drives.
The ClamWin Portable antivirus scanner supports scheduled virus scans, can update the virus definitions on an as-needed basis, includes a plug-in to scan email in MS Outlook, and can check for threats in folders or individual files.
Three simple scan types to check areas where threats are commonly found, to scan the whole computer, or to check for malware only in specific places of your choosing. Can scan for MBR changes, check inside archives, skip files that exceed a certain size, and more. Includes an auto-run analyzer for deeper threat inspections.
It’s a fairly large download but still completely portable. This portable virus scanner is great for if the virus is blocking these other downloads because this one saves to your computer with a unique name each time it’s downloaded.
Most of Emsisoft’s antivirus programs cost, and some are for business use. This free virus scanner is still useful, however, and even updates often with new and better features. This portable scanner can run a quick scan against actively running programs, a malware scan against areas common threats exist, or a custom scan. You can also exclude files/folders from scans. This download is over 300 MB and extracts to a folder that requires over 700 MB. It runs on Windows 7 and newer.
This portable scanner, also called MWAV, is over 200 MB, so it’s definitely not your average virus checker. When you open it, it automatically unloads its program files to a temporary folder. You can use MWAV to scan the memory, services, startup folders, hard drive, registry, system folders, specific folders, archives, and/or portable drives.
Scan specific files, whole folders, entire hard drives, network folders, memory, auto-start locations, and removable drives.
At hardly 5 MB, this is an ultimate portable virus scanner. It’s been used by many to get a full list of what’s happening on the computer right now. It also serves as a HOSTS file editor, registry key unlocker, file unlocker, service deleter, process manager, and more.
HouseCall is a portable virus scanner from Trend Micro, a popular cyber security company. It runs full/quick/custom scans to remove viruses, worms, spyware, and other malicious threats. It can also locate vulnerable devices on your network, and it does it all in a compact and easy to use portable program.
This portable rootkit scanner installs to any folder of your choosing, and needs around 5 MB of space. You can pick to scan in any or all of these locations for rootkits: BIOS, system memory, services and drivers, boot sectors, and loaded modules. View the report file to copy/see the results.
This single file you can download from Kaspersky’s website is over 150 MB. It takes a couple minutes to full load when you first open it, but when it’s ready, you can use this portable virus scanner to delete adware, riskware, and other malware. It checks any specific folder, the system memory, startup objects, boot sectors, and the system drive. Items this scanner finds goes into the quarantine section where you can deal with them.
This free virus scanner from McAfee checks your computer for suspicious files by combining heuristics and the McAfee Global Threat Intelligence (GTI) File Reputation database. It’s super lightweight, downloads quickly, and has just a few options to make using it rather easy. A report opens when it’s done scanning that shows any suspicious files.
McAfee Stinger can detect and remove thousands of viruses. It needs a total of less than 20 MB of space to run, automatically quarantines threats, and can scan any specific folder you choose. Start a scan immediately or go into the settings to scan specific things like the registry, WMI, rootkits, processes, and boot sectors. You can also enable subdirectory and archive scans. One unique feature you get with this free portable virus scanner is the ability to blacklist certain files based on their MD5 hashes.
Microsoft’s portable virus scanner can check for viruses via a quick, full, or custom scan. It’s over 100 MB and runs from a single file. Download the 32-bit or 64-bit version depending on the version of Windows you have. It works on Windows 7 and newer.
This portable virus scanner is over 300 MB, but that just goes to show that it’s full of features. There are several tabs that run along the top to access all parts of the software. You can run a quick, full, or custom scan, exclude files/folders from a virus scan, unpack archives, scan for rootkits, detect PuPs, control forensic options, edit quarantined items, and more.
From one of the biggest companies in the digital security space, Norton Power Eraser is a portable antivirus solution that lets you do quite a bit all for free. You scan for unwanted applications, run a full system scan to delete rootkits, check for threats on another operating system on your computer (in a multi-boot scenario), and perform a Norton Cloud reputation lookup on any file/folder you choose.
Extract the files from this portable virus scanner (requires around 20 MB) and run the program to clean up viruses on any hard drive attached to your computer. It scans everything on the drive without any complex or unnecessary settings, but that also means it’s not very customizable. It scans processes first and then checks for file viruses.
This portable virus scanner is pretty portable indeed; at just 5 MB, it’s a great addition to any collection of malware cleaners. It includes three tabs for Spy Scanner, Process Viewer, and DLL Tracer. The settings let you toggle various options, like to scan for hidden processes and DLLs.
As the name suggests, this portable scanner checks for spyware, specifically. If you don’t want your web browsing habits to be tracked, consider using the Spybot portable virus scanner to immunize your computer, check for temporary files that can be removed, find tracking cookies, and more. You’ll need over 300 MB to store this program.
The StreamArmor portable virus scanner is another program that can run from a single file that’s under 5 MB. It can perform a complete scan of your computer to find viruses, or you can choose any specific folder to check. Settings let you enable subfolder virus scans, ignore data files like thumbs.db, run the program at Windows startup, and more.
This is one of the bigger downloads at over 150 MB, but it’s a nice portable virus scanner that you should still consider using. Zillya is a reputable company with robust commercial antivirus software, but this free portable scanner still lets you run a quick, full, or custom scan to delete viruses from your computer. A custom scan can check potentially dangerous files on any and all your connected hard drives, and can run either a quick scan which checks only dangerous file types, or a full scan to look for viruses in every single file on your computer.