What are you to do when you have a computer problem so bad that your computer won't start at all, and you're pretty sure a virus or some other malware is to blame? How do you scan for viruses when you can't start Windows to do a virus scan?
This is where a bootable antivirus program becomes the hero of the day. With one of these scanners, you create a special flash drive or CD/DVD disc from a working computer and then use it on the infected machine to scan the hard drive for viruses—all without needing to start Windows!
Since the most serious of viruses cause damage to the parts of your computer that allow it to start, a bootable antivirus tool can often be a powerful weapon at your disposal for getting the virus removed and your computer back up and running.
In general, using one of these programs requires that you take the ISO image provided and then, from a working computer, burn it to a disc or burn it to a USB drive. Next, you'll need to boot from the disc or boot from the flash drive on the infected PC. More details are available in our reviews and on most of the websites linked below.
Really easy to use
Lets you scan the whole drive or certain folders only
Can run a quick or full scan
Able to repair malicious changes made to the registry
Relatively small download size
Can't scan specific files only
No longer gets updated
Anvi Rescue Disk is a really simple bootable virus scanner. There are only three main scan buttons, two sections to the program, and no custom settings.
You can run a quick smart scan, a full system scan, or a custom scan to search for malware inside one or more specific folders.
There's also a section for finding and correcting corrupt registry issues that may have been altered by a virus.
The only thing we don't like about Anvi Rescue Disk is that you must scan the whole drive at once—you can't choose to scan single, specific files like you can with regular antivirus software.
Scans things most bootable AV programs do not
Lets you check for viruses on any attached hard drive
Includes other tools like a hard drive tester
Doesn't have a graphical interface like most programs, so it might be hard to use if you're not used to that type of UI
Doesn't offer definition updates
AVG Rescue CD is a text-only free bootable antivirus program. It can check for potentially unwanted programs, scan cookies, find hidden file extensions, and even scan inside archives.
Before you start a scan, you have the option to just check a folder of your choice, just the boot sector, only the registry, or any locally attached hard drive.
Unfortunately, because AVG Rescue CD doesn't provide a graphical interface, navigating the menus can become difficult.
AVG no longer updates or maintains this program, so the virus definitions will forever be outdated. You can still scan normally, but it won't catch brand new threats.
You can scan specific files/folders or the whole drive
Includes an option to skip scanning certain files
Supports multiple scan types based on what you want to scan
Lets you pick between a graphical UI and one that's text only
Checks for updates automatically
Relatively small download size
It's difficult to use the file/folder-level scan option
The program itself hasn't been updated in a long time
In addition to the regular, installable Comodo Antivirus software, Comodo also has a free bootable antivirus program.
Comodo Rescue Disk can be launched from a USB device or disc in either text-only mode or with a full graphical user interface (GUI). The GUI version has a familiar program interface which is much easier to use.
There are three different scan types: smart scan, full scan, or custom scan.
Smart scan checks for viruses and rootkits in the memory, boot sectors, autorun entries, and other areas like the registry and system folder. A custom scan lets you choose individual files and folders to scan instead of an entire drive.
You can also scan archives, enable heuristics scanning, and skip files over a specified size.
It's a plus that Comodo Rescue Disk includes a familiar Desktop-like interface because it makes it easier to use than some of these other text-based scanning tools.
Custom options not found in some of these other bootable AV programs
Lets you define the types of files it should scan
Checks for virus definition updates from within the software
Runs from a disc or flash drive
The large setup file might take a while to download for some
Dr.Web LiveDisk is a feature-filled free bootable virus scanner for Windows and Linux.
There are plenty of configurable settings, like choosing the actions Dr.Web should take when finding infected, suspicious, or incurable files. Also, you can set what should occur in the event it detects specific issues like adware, dialers, jokes, hacktools, and riskware.
The program lets you exclude directories from being scanned, set how large a file can be before it's excluded from a scan, and define a maximum duration it's allowed to spend scanning a single file.
We like that Dr.Web can check for virus definition updates directly from the program. This means you can reuse the software in the future and all you have to do is update it before you do a scan.
You can install this AV program to a USB device or a disc, but either method is still a rather large download, at over 800 MB in size.
Lets you scan specific folders, the whole drive, and other areas
Scans for many types of malware
You get to choose which interface to use: graphical or text
Includes other tools
Large download at around 600 MB
Kaspersky has what's called a Rescue Disk, which can scan for viruses, worms, Trojans, malicious tools, adware, dialers, and other malicious items.
You can pick between using the graphical mode (recommended) or the text-only mode.
Your scan options include Fileless objects, Startup objects, and System drive. You can also scan boot sectors and specific folders.
Kaspersky's tool can also browse through the file system to copy or delete files. The Firefox browser is also built in, among many other tools.
The only downfall is that the file is rather large, and may, therefore, take some time to download.
Can scan specific files, folders, and hard drives
Small download size (under 200 MB)
Doesn't function as a true bootable AV program
Doesn't work if the virus is blocking access to your computer
Isn't as easy to use as similar tools
Panda Rescue ISO is a program that allows the free Panda Cloud Cleaner program to scan a computer without any other running processes that could potentially shut it down and prevent a virus scan.
First, you must boot to the Panda Rescue ISO disc to prepare your computer for running Panda Cloud Cleaner. Next, your computer will reboot into Windows but launch the cleaner before any other applications start. All other processes are shut down so that this program is less likely to be terminated by a virus.
One problem with this tool is that it may not work properly if a virus has infected your computer so deeply that you can't even boot into Windows. If this is the case, you'll want to try any of the other tools in this list that don't require Windows to start.
Supports two scan types
Includes an option that lets you delete specific files
Runs in a text-only mode
Lacks custom scan options
Takes a while to reach the actual download page
Not many custom settings or options are available in Sophos Bootable Anti-Virus except choosing one of two different scan types.
A Recommended Scan can either rename infected files or just display a log of the malicious items that were found. An Advanced Scan will actually remove any infected files it detects.
There's also a Bash Shell menu option for manually removing viruses. This option is only useful if you know where the malicious items are, which isn't very likely.
You must answer several questions before you can get to the download link.
Advanced steps are necessary to get the Sophos Bootable Anti-Virus ISO file. You must read the instructions carefully in order to download the program. It ends up requiring a few hundred megabytes of free space.
There are two scan types you can run
Fairly easy to use considering the lack of advanced options
Doesn't have a graphical interface
Trend Micro Rescue Disk is another free bootable antivirus tool that doesn't have a graphical interface, meaning you'll need to navigate entirely in text mode with the arrow keys.
You can run a quick scan or a full scan, depending on what areas you'd like checked.
It's first downloaded as a regular program file that includes the bootable software. It works in Windows 11, 10, 8, 7, Vista, and XP. Just choose to install it on a USB device or CD.
Several exclusion settings to customize the scan
Virus definition updates are supported directly from the disc
Has a graphical UI instead of text
Downloads as an EXE file instead of directly as an ISO
Windows Defender Offline is a bootable virus scanner from Microsoft that sports a full user interface.
You can update the virus definitions directly from the disc, view quarantined files, and exclude files, folders, and extension types from scans.
Windows Defender Offline supports quick virus scans, full scans, and custom scans so that you can choose your own folders and drives to scan.
The Windows Defender Offline tool from the download page can burn the software to a disc or USB device for you, so no image burning software is necessary. Microsoft says the directions on the download page are for Windows 11, 10, 8, and 7 users.
Runs with a full desktop interface
Lets you scan a whole drive or specific folders only
Includes a tool to fix corrupt MBR problems
Easier to use than some bootable AV programs
Lacks really advanced scan settings found in similar programs
Can't scan specific files only
Zillya! LiveCD can scan entire drives or whole folders only, so it won't scan just single files.
There's an option to check for viruses in potentially dangerous file types like executables so that you're not scanning every single file type, which could take a long time.
A utility called Zillya! MBR Recovery is available from this bootable disc, which can scan the MBR for viruses and attempt to fix boot issues caused by a corrupt MBR.
We like all the settings that are included, as well as the fact that it provides a very easy to use interface.
Super easy to use
Advanced settings if you want to use them
Complete desktop environment
ESET SysRescue is another bootable virus scanner that you can use for free from a CD, DVD, or USB device. It comes from the company ESET, which also sells security software for home users and businesses.
This tool provides a full desktop environment, so if you're uncomfortable with text-only user interfaces, you should be okay with how this one works. There's a start menu, desktop items for other tools like GParted, a file browser, and of course a shortcut to ESET SysRescue.
The virus scanner itself is very easy to use and can be used quickly without any customizations. From the On-demand scan page, just choose the option you want to use: Smart scan to check only some areas for malware—specifically, common locations malware is found; or choose Custom scan to run an in-depth, full scan of any area of the drive, including the whole thing.
However, you can change advanced settings if you want. Some scan settings include choosing which object types to scan—such as files, symbolic links, email files, archives, self-extracting archives, boot sectors, and others. You can also enable heuristics, detect PuPs, exclude specific file extensions, and set scan limits on files of a certain size.
When you first run the program, you're given the option to not only run the virus scanner, but also check for errors on the disc or in the memory.
Boots to a fully interactive desktop.
Mostly automatic; known risks are deleted for you.
Zero advanced options means you can't customize it.
It's unclear what it looks for.
Doesn't seem to stay current with virus definitions.
The makers of the popular Norton Antivirus software have this free bootable recovery tool available. It scans your computer for security risks and removes them automatically, or lets you decide what to do if it's a potential risk.
There's also a file retrieval option that helps you copy data from your computer to another drive, such as a removable hard drive.
This is a full desktop experience, so you use your mouse to navigate. There's also a terminal window for running commands, and the Opera web browser if you need it.
Norton has directions for putting this ISO file on a DVD or USB device if you need help.
Uses a regular, graphical interface instead of text only
Includes other tools like a browser and file explorer
Scans a whole partition at once without the option to check particular files only
Doesn't update with newer definitions
Large download, over 1 GB
Avira Rescue System is a free bootable antivirus program that's incredibly easy to use. If you've tried running a bootable AV program before, but it was too confusing, try this one.
You can't scan individual files, only a whole drive at once, but there are other tools that come with it that you might find useful.
Has lots of scan options you can tweak
Might be hard to use because of the text-only interface
Download is around 200 MB
VBA32 doesn't support a graphical interface, but it makes up for it in its detailed settings.
There are plenty of options in this program, like choosing which drives to scan, defining a set of file types to scan, choosing to scan inside archives, and deciding a default action when a malicious file is detected.
You can also adjust the heuristic scan settings and update virus definitions directly from the CD or USB drive.
The obvious downfall to VBA32 Rescue is that you must use it in a text-only mode, unlike most of these other tools that have a regular, graphical interface.
Easy to use because there aren't lots of options to get confused about
Not as large of a download as some similar programs
Updates are no longer performed
Doesn't have advanced scan options
Missing the familiar graphical UI
F-Secure Rescue CD is a simple bootable antivirus program. It works without any graphical user interface, so it might be a bit confusing.
There are hardly any options or user input except pressing the Enter key to confirm the start of a scan.