13 Best Lightweight Antivirus Software for Old PCs
Get the best antivirus solution for your old PC ?
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Key notes
- Older PCs have special requirements when it comes to antivirus tools, such as low CPU power.
- They also have lower memory space, so it's important to get an AV with a small file.
- Because of that, we've compiled a list of the best premium antivirus tools for old PCs.
- If you want to try out the software before you buy them, know that many include free trials.
If you are still keen on using older devices, you need to use a lightweight antivirus for your old PC.
Antivirus software has become vital in this age of web surfing as computers need protection from Internet-based malware and other offline threats.
This can pose problems with PC users of older Windows OS such as Windows Vista, Windows XP, Windows 2000, Windows NT, etc. However, there’s still antivirus software for Windows XP Service Pack 3.
Although the obvious choice should be to replace such PCs, sometimes users get attached so they continue using them.
For that, we have compiled some of the best antiviruses that run efficiently on older PCs with a focus on their functionality and effectiveness.
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Why do you need a lightweight antivirus for an old pc?
Older PCs have lower RAM memory and disk space as well as slower processors, so it is important to use a light antivirus utility to protect them.
Antiviruses that have a smaller footprint on your system let you use other apps while scanning. You can leave them in the background without worrying about interruptions.
Here are some of the key benefits of a lightweight antivirus:
➡️ Requires less disk space and installs faster
➡️ Can run in the background without slowing down your PC
➡️ Uses less CPU and memory when running scans
➡️ Stays up-to-date without taking a toll on your resources
Best lightweight antivirus software for Windows old pc (Windows XP, Vista, 7, 8/8.1, 10)
| Antivirus Name | Supported Operating System | Processor Requirements |
| ESET NOD32 | Windows 7, Windows 8, 8.1, Windows 10, Windows Server 2011 | Intel® or AMD x86-x64 |
| Bitdefender | Windows 7, Windows 8, Windows 19, Windows 11 | Any processor, but older ones may affect performance |
| TotalAV | Windows XP, Windows Vista, Windows 7, Windows 8, Windows 10 | Intel/ AMD 1.6 GHz or faster |
| Panda Security | Windows XP, Windows Vista, Windows 7, Windows 8, Windows 10 | Intel Pentium 300 MHz or faster |
| Avira Antivirus | Windows 7 or newer | Intel Pentium 4 / AMD Athlon 64 Processor or newer |
| Kaspersky Internet Security | Windows 7 or newer | Intel Pentium 1 GHz or any other faster processor |
| Intego360 Total Security | Windows 7, Windows 8, Windows 10, Windows 11 | Any processor, but older ones may affect performance |
| Webroot SecureAnywhere | Windows 7, Windows 8, Windows 10 | Intel/Pentium/Celeron/AMD or other that meet OS requirements |
| Avast Free Antivirus | Windows 7, Windows 8, Windows 8.1, Windows 10, Windows 11 | Intel Pentium 4 / AMD Athlon 64 processor or faster |
| AVG | Windows Vista, Windows 7, Windows 8, Windows 10 | Intel Pentium 1.5 GHz or faster |
| Secure APlus | Windows 7, Windows 8, Windows 10, Windows 11 | Intel Pentium 4, 2GHz or faster |
| Clam AV | Windows 98, Windows Me, Windows 2000, Windows XP, Windows Vista, Windows 7/8/9/10/11 | Any processor, but older ones may affect performance |
Which free antivirus uses the least memory?
Antivirus software uses memory differently depending on the tasks they employ. Most antiviruses are left to run in the background to detect real-time threats.
That is the idle memory usage and is pretty low for most antiviruses. They may use more memory when performing regular full PC scans or full scans.
Many users say that free antivirus software does use up more memory space, but there are some utilities that are not as demanding as others:
| Antivirus Name | RAM usage (MB) |
| Avast Free Antivirus | 6.3 MB |
| Panda Antivirus | 9.8 MB |
| BitDefender | 14.9 MB |
| Kaspersky | 23.4 MB |
| AVG | 29.5 MB |
RAM usage rates vary, but these are the medium values that have been found when running a regular PC scan.
Which is the best antivirus for old PCs that I can get?
ESET NOD32 Antivirus – Good management system
The top lightweight solution on the market for low-end PCs is ESET NOD32. When it comes to resource consumption, an older PC might not hold up with the stress caused by demanding antivirus software.
Antiviruses are known to take a toll on the system they’re installed in, especially when doing thorough scans.
Thankfully, ESET is able to manage your system, protect it, remove malware, and perform periodic scans without affecting its performance.
The Advanced memory scanner feature will decrypt, analyze files and monitor malicious behavior through a specialized algorithm that doesn’t sacrifice CPU power to run.
ESET NOD32 Antivirus
Keep your old PC secure with ESET NOD32 Antivirus, the most lightweight and up-to-date software.Bitdefender – Exclusive adaptability technology
Next, we have a tool that has been on the market for a long time. Bitdefender Internet Security is well known for its powerful capabilities to detect, block, and remove cyber threats.
It is built by a strong development team that aims to offer comprehensive protection. Its detection mechanism does not use too many system resources, so it is suitable for older PCs as well.
It uses Bitdefender Photon which is an exclusive technology that makes the software adapt to your system hardware and software configuration. It saves resources and improves performance and speed rates.
Bitdefender uses machine learning to detect suspicious behavior in your system It also has a strong database that is constantly updated with current information about the newest threats.
The tool has a powerful vulnerability assessment feature that can be very useful for users of older PCs. It identifies outdated or unsecured software, missing security patches, and other holes that can lead to infection.
With this antivirus, you get complete protection against all the cyber threats of today. It protects against viruses, malware, ransomware, phishing attacks, fraud attacks, and more.
BitDefender Internet Security
Equip your PC with a powerful security software that protects you on all fronts without requiring too many resources.TotalAV – Fast and efficient software
TotalAV is also a lightweight software that doesn’t impact your computer performance and still provides outstanding protection.
It instantly detects and blocks malicious websites and content to keep your personal data safe and secure. It also checks your downloads and executables for threats and viruses every time your PC accesses them.
TotalAV helps you encrypt your connection by leaving no digital footprints and making your activities anonymous and impossible to track.
You can easily generate strong and unique passwords for all your online accounts and keep them safe behind a vault.
Remove harmful threats from your PC and schedule smart scans to run at your set time and ensure your system remains protected at all times.
TotalAV
Take full advantage of TotalAV’s comprehensive protection and safeguard your PC.Panda Security – Simple usage
Panda Security is known for its pleasant user experience. It has a simple application with intuitive options.
The tool is light but strong in terms of protection capabilities. It is fast responding with real-time antivirus and anti-malware alerts.
It has low resource usage when running in the background and does not take up too much memory space when scanning either.
The antivirus can block online cyberattacks with its strong Firewall that can run alongside the Windows built-in Firewall.
Along with that, it includes a VPN that enables you to have a more secure online experience. It can help protect sensitive data such as your location, bank information, and identity.
Panda is great if you use older OS versions. It works on Windows operating systems starting with Windows XP 32-bit.
Panda Antivirus
Don’t compromise between security and performance and enjoy real-time protection with minimal system requirements.Avira Antivirus – Thorough scan
Another great and free option on our list is Avira. The software performs very well on older PCs, and it’s proven to be one of the best antiviruses currently.
You will be able to perform thorough scans of your computer without encountering any problems. Besides that, Avira can also help improve your PC’s performance by removing unwanted files.
The antivirus has both a full scan and quick scan feature and is always running in the background to stop incoming attacks.
The file remover will clean your PC of unnecessary junk files and bloatware and make it run faster.
Avira will also protect you from suspicious websites and keep your identity private. To top it all off, it also includes a free VPN for extra safety.
The VPN can protect your online activity, making for more secure payments and personal data sharing.
Avira Antivirus
Lightweight and fast, Avira will protect you from current and new threats.Kaspersky – User-friendly program
Kaspersky Antivirus is one of the most widely used antivirus software in the world which gives protection against malware.
The Antivirus uses a layered defense posture to scan your system quickly without giving false positives.
It is also compatible with older versions of Windows OS including Windows XP and Vista which makes it a good choice for users with older PCs.
This program includes file scanners, software uninstallers, gamers’ mode, ransomware decrypter, system restore, virtual keyboard, cloud protection, browser configuration, rescue disk, etc.
In addition, one of the unique features of Kaspersky is that it requires 512MB Ram and 480MB disk space to run.
This makes it a great option for older PCs especially PCs which have 1GB Ram and slower processors.
Kaspersky
Award-winning security from a well-known provider in the security field for over 20 years.Intego – Exceptional online threat monitoring
Intego is our second choice when it comes to world-class and lightweight antivirus programs for old computers.
It has a low-resource usage so you don’t have to worry about slowing down your device’s performance and state.
Intego can help you not only exterminate all types of cyber threats but prevent them from destroying your PC’s health as well.
It is very easy to work with because it has an intuitive user interface and offers advanced technology that keeps your old PC safe with real time monitoring.
Intego is a well-known and recommended antivirus software thanks to its excellent digital threat detection capabilities and improved security.
Intego
Improve your old PC’s security without affecting its performance by using Intego.Webroot Secure Anywhere antivirus – Impressive security tool
Next, Webroot Secure Anywhere is a web-based antivirus for your old PC.
This antivirus incorporates premium security features in a tiny little package; hence, few computer resources are utilized while providing excellent protection to your old computer.
The tool protects you against web attacks with a strong firewall, as well as web filtering. This stops hackers from trying to steal your data.
This antivirus has other impressive Internet security tools, as well as a high detection rate for all sorts of threats including ransomware and malware.
The activation adds a password manager as well. In addition, this tool has very good detection rates for malware and virus threats with anti-phishing features.
Webroot Secure Anywhere
Give your old PC a modern-day antivirus to protect it. Choose Webroot as your go-to security system!Avast Free Antivirus – Strong secure connection
Avast is a worldwide giant in the antivirus industry with hundreds of millions of users worldwide.
If you want an efficient antivirus for your old PC, look no further than Avast Free Antivirus. Moreover, it is compatible with all Windows OS.
This tool comes with features such as a file scanner, Windows Explorer context menu integration, Rescue Disk, password manager, junk file cleaner, Wi-Fi inspector, Game Mode, and browser cleaner.
The Wi-Fi inspector ensures that you have a secure connection even when connecting to a public network.
When you activate the Game mode, certain notifications and pop-ups will be temporarily disabled so you will not be interrupted.
In addition, Avast Free Antivirus comes with web, behavior, and mail shields. You can download the software from the official website.
Avast Free Antivirus
Protect your outdated PC with Avast Free Antivirus, one of the best lightweight apps on the market!AVG – Powerful blocking feature
AVG is a full-featured antivirus utility. It is capable to offer well-rounded protection against all cyber threats.
This antivirus can detect and remove well-known threats as well as new, emerging ones. It blocks suspicious activity that could signal an infection.
It blocks insecure downloads and email attachments, ransomware, spyware, viruses, and other types of malware.
If you use an older PC, this antivirus can be of help. Not only is it lightweight, but it also has a performance scanner feature.
It lets you know whether there are any faulty settings or outdated apps that slow down your PC.
AVG performs well on PCs with lower memory, even when scanning or installing updates.
The premium version of the software has added benefits such as an Enhanced Firewall and 24/7 customer support.
AVG
Protect and optimize your PC’s performance with this up-to-date antivirus.SecureAPlus – Customizable interface
This is a web-based antivirus program that combines major antivirus programs together. SecureAPlus is ideal antivirus software for users of old PCs that can decide on an antivirus.
In addition, it gives access to multiple antivirus engines. As it is mostly cloud-based it does not put much stress on your computer’s resources.
SecureAplus gives you the opportunity to test the products with features such as real-time protection, detection ratio, firewall, anti-phishing, scan speed, and resource consumption.
However, SecureAPlus is cloud-based and integrates 12 popular antivirus engines into one with a customizable interface for trusted programs.
The antivirus engines include AVG, Avira, BitDefender, ClamWin, ESET, Emsisoft, McAfee, Microsoft Security Essentials, Norman, Quick Heal, Sophos, and Total Defense.
Clam AV – Multiple versions available
Up next we have an open-source antivirus that is capable to run quick scans without impacting PC performance.
It is a cross-platform antivirus software with a very small file. It supports both 32-bit and 64-bit builds for Windows.
It is a command-line antivirus, but it also has a dedicated application for Windows users. Both are completely free and open-source.
The benefit of this software is that it gets more frequent updates. This means that it is able to detect and block new threats with high accuracy.
The tool has multiple versions available, you can select your preferred option when you download it.
Clam AV is able to protect your email with built-in support for all email file types. It also scans files and apps and does not let you start them until it’s clear they are secure.
This antivirus is for the most part used for its file scanning and email protection capabilities.
Despite the fact that it is able to detect and remove PC malware, it specializes in that area.
It can thoroughly scan all major document file formats including PDF, HTML, and DOCX.
Why do you need a lightweight antivirus for an old PC?
A lightweight antivirus is a safe solution for an old PC because it is a program specially created to take minimal impact on your computer and not slow down its performance at all.
Some of them even have advanced technology that knows when you’re gaming, for instance, and doesn’t interfere with your activity to avoid slowing down your PC.
Do share with us your experience in using any of the antiviruses for the old PC which we mentioned above. We do appreciate your feedback when you comment below.
Please keep in mind that these tools are also recommended for the following use cases:
- Antivirus for very old PC – Some of the tools have such low system requirements, that they qualify as very old computers.
- Best antivirus for old slow XP PC – Some really old PCs keep using Windows XP. While the OS is not recommended, take a look at the antivirus for Windows XP.
- Best free antivirus for old laptop – Some of the solutions presented also offers a free version that has limited functionality. You could use that before upgrading to the premium edition.
The lightest antivirus for Windows 7 is the ESET NOD32 antivirus software solution.
The most lightweight free antivirus you can opt for is the Bitdefender antivirus program.
Without specialized software and security updates, Windows 7 can be prone to virus damage.
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