Configuring Antivirus Software for Efficient Scanning That Doesn’t Slow Your PC

Chris Hoffman 08-02-2013

Antivirus software is important on Windows, but it can slow down your computer. The on-access scanning that protects you from malware What Is The Difference Between A Worm, A Trojan & A Virus? [MakeUseOf Explains] Some people call any type of malicious software a "computer virus," but that isn't accurate. Viruses, worms, and trojans are different types of malicious software with different behaviors. In particular, they spread themselves in very... Read More means your antivirus has to scan every file you access before it actually opens. Luckily, there are a variety of ways to speed things up without losing security.


Heavy antivirus programs can slow down a computer – particularly an older computer running an older, poorly optimized security suite. Norton and McAfee were some of the worst offenders How To Completely Remove Norton Or McAfee From Your Computer Read More , but have improved with recent versions. Making sure to configure an up-to-date antivirus is one of the most important things you can do.

Configure Exclusions

Antivirus applications normally scan every file you access before allowing them to open. If you have files that you consistently access, such as virtual machines What Is a Virtual Machine? Everything You Need to Know Virtual machines allow you to run other operating systems on your current computer. Here's what you should know about them. Read More , you can exclude them. Your antivirus will ignore any excluded files, allowing them to open without any scanning.

For most files, exclusions won’t offer very large speed-ups. However, for large files or lots of little files, especially ones that change frequently, exclusions may help. If you exclude your virtual machine directories, you may see a significant performance boost in your virtual machine performance.

Note that exclusions can be potentially dangerous. If you exclude your entire C:\ drive or exclude all .exe files, you may as well not be using an antivirus at all. Be smart about the exclusions you configure. For example, you wouldn’t want to exclude your Downloads directory.

To configure exclusions on Microsoft Security Essentials in Windows 7 or Windows Defender in Windows 8 Five Surprising Facts About Windows 8 Windows 8 is full of surprising changes – whatever you think about Windows 8, Microsoft certainly isn’t being timid this time around. From integrated antivirus protection and less-disruptive updating to the removal of the Windows... Read More , open the application and click the Settings tab. You can exclude specific files or folders, exclude all files with a specific files extension, or exclude processes with a certain name.


configure antivirus software

For example, if you want to exclude your virtual machine folder, select Excluded files and locations, click the Browse button, and select your virtual machine folder. An antivirus application can’t protect against viruses inside a virtual machine, anyway – it can’t “see into” the virtual machine.

Use Gaming Mode

Some antivirus applications offer a “gaming mode”  toggle, but this won’t increase your performance as much as you might think. “Gaming mode” generally disables notifications 5 Distracting Desktop Notifications & How To Turn Them Off [Windows] When you are working on a computer, it takes a fair bit of will power to resist the attempt to multitask. But even if you manage to restrain yourself, many programs manage to throw in... Read More and other pop-ups so they won’t bother you while you’re playing a game 6 Ways to Make Money Playing Video Games You can make money playing video games, but it isn't easy. If you are dedicated, this article covers how a hobby can make money. Read More or watching a movie 6 of the Best Streaming Media Services Compared Streaming media has become the way of the future for many consumers, and as a result there’s no shortage of services to pick from. Let’s compare five of the best streaming media services to see... Read More . That’s why this feature may also be called “silent mode.”

However, gaming mode does have some benefits. While in gaming mode, antivirus applications will usually delay scheduled scans and automatic updates.


Some antivirus applications may try to automatically enable gaming mode when you have games open. For example, Bitdefender will automatically enable gaming mode when you’re playing games it recognizes, but you can also enable it manually by right-clicking the Bitdefender system tray icon Manage And Tidy The Windows 7 System Tray Every Windows user has seen the Windows system tray (also known as the notification area) become cluttered over time. We’ve covered disabling distracting desktop notifications in the past, but what if the icons themselves are... Read More and selecting Turn Game Mode On.

configure antivirus

Tune Your Scan Schedule

Antivirus applications are usually set to perform automatic, scheduled scans. These scheduled scans can occur while you’re using your computer, slowing things down.

You can generally choose a scheduled-scan time from within your antivirus application. For example, you’ll find these options under Scheduled scan on the Settings tab in Microsoft Security Essentials (or Windows Defender on Windows 8).


By default, Microsoft Security Essentials is set to run a quick scan on Sunday at 2 a.m.. It will run only if you’re not using your computer and limit the CPU usage during the scan, so it won’t slow things down too much. However, other antivirus applications may not be so considerate. Check the scheduled scan options in your antivirus to find out.

configure antivirus

Exclude Removable Drives

Some antivirus applications automatically start scanning USB drives, CDs, and DVDs when you insert them into your computer. The entire-drive scanning feature can help you identify drives that have malware on them, but it also makes you wait before you can use the drives at full-speed.

This option is often located in the same place as the Exclusions settings in your antivirus program. If you don’t see these options, your antivirus may not have this feature (Microsoft Security Essentials doesn’t have this feature enabled by default).


Your antivirus will still check files that you open from the removable drive as they’re accessed. However, it won’t scan the entire drive when it’s inserted.

configure antivirusb

Choose On-Access Scan Settings

More heavyweight antivirus applications may have a setting that controls how much system resources their on-demand (also known as real-time) scanning software uses. For example, in Bitdefender, you can select Aggressive, Normal, or Permissive on-access scanning. The more aggressive options take more system resources.

You may also be able to control more detailed settings, such as choosing whether or not your antivirus scans inside zip files and other archives What’s The Best File Compression Method? MakeUseOf Tests Zip, RAR & More File compression is an important and common task users frequently ask of their computers. Reducing a file’s size makes it easier to email or place on a flash drive. It also reduces bandwidth usage and... Read More . This takes more system resources.

configure antivirus

Focus On Your System Drive

When performing full-system scans, you may want to focus on scanning your system drive and scanning other drives less frequently. For example, if you have a 2 TB drive full of media files – especially an external one that takes longer to access – you may want to prevent your antivirus from performing long scans on it.

Assuming you don’t store programs on the secondary drive, you shouldn’t need to scan it as frequently. If malware does make its way onto the drive, your antivirus should protect you if you ever try to open it.

Your system drive – almost always the C:\ drive – is the most important location to scan.

configure antivirus

Use a Lightweight Antivirus

This is the most controversial advice here. Antivirus providers are constantly trying to sell us more feature-packed, do-everything solutions. However, you don’t necessarily need an Internet security program packed with everything but the kitchen sink. Internet security suites often include firewalls and phishing What Exactly Is Phishing & What Techniques Are Scammers Using? I’ve never been a fan of fishing, myself. This is mostly because of an early expedition where my cousin managed to catch two fish while I caught zip. Similar to real-life fishing, phishing scams aren’t... Read More  filters, but Windows includes a firewall and all modern browsers (even Internet Explorer 7 Useful Tips & Tricks For Internet Explorer 9 Users Tech websites write a lot about Google Chrome and Mozilla Firefox, so it’s easy to feel a bit left out if you use Internet Explorer. Internet Explorer 9 is easily the best version of Internet... Read More ) include their own phishing filters.

If your antivirus is weighing your computer down, you should consider looking at a more lightweight, speedy solution. I’ve long loved the free Microsoft Security Essentials – available for Windows 7 and included on Windows 8. It doesn’t do everything, doesn’t slow down your system, and doesn’t try to up-sell you to a paid antivirus product. However, Microsoft Security Essentials has taken a bit of a beating in some antivirus tests recently and Matt has recommended using another antivirus product instead of Microsoft Security Essentials Free Anti-Virus Comparison: 5 Popular Choices Go Toe-To-Toe What is the best free antivirus? This is among the most common questions we receive at MakeUseOf. People want to be protected, but they don’t want to have to pay a yearly fee or use... Read More . On the other hand, real-world test results for Microsoft Security Essentials have been fairly good.

Either way, I still use – and like – Microsoft Security Essentials (Windows Defender on Windows 8). Your mileage may vary, and that’s okay.

configure antivirus software

You could also disable on-demand scanning (also known as real-time scanning) and manually scan files when you download them. However, we don’t recommend this. It won’t help protect you against malware that arrives via security vulnerabilities, such as the security holes in Java Is Java Unsafe & Should You Disable It? Oracle’s Java plug-in has become less and less common on the Web, but it’s become more and more common in the news. Whether Java is allowing over 600,000 Macs to be infected or Oracle is... Read More and flaws in other browser plugins like Flash Browser Plugins - One of the Biggest Security Problems on the Web Today [Opinion] Web browsers have become much more secure and hardened against attack over the years. The big browser security problem these days is browser plugins. I don’t mean the extensions that you install in your browser... Read More . Better safe than sorry – particularly since a well-configured, speedy antivirus won’t noticeably slow down your PC.

What other tips do you have to configure antivirus so that it doesn’t slow down your computer without giving up on security? Leave a comment and share them!

Affiliate Disclosure: By buying the products we recommend, you help keep the site alive. Read more.

Whatsapp Pinterest

Leave a Reply

Your email address will not be published. Required fields are marked *

  1. Igor Rizvi?
    February 13, 2013 at 6:13 pm

    Iv used bitdefender in game mode, micrsoft antivirus,and alot of mroe antiviruses..and you can sense alot of performance drawback on the pc while playing,surfing ect...

  2. Efi Dreyshner
    February 12, 2013 at 6:00 am

    Bitdefender is too much "heavy"...
    I am using Avast :)

  3. richardL
    February 8, 2013 at 10:14 pm

    Exclude removable drives?????????

    This is NOT good advice - a great many viruses spread via USB storage using autorun.inf and other features which many users have on by default. Relying on scanning opened files will not exclude this most common of risks.

    I'd consider removing this advice, to be honest!

    • Lisa Santika Onggrid
      February 11, 2013 at 7:16 am

      Definitely. This is very dangerous except you plug nothing but your trusty always clean, private removable drives which is unlikely if you use it for what it does (moving data around)

    • Brian Lawrence
      February 14, 2013 at 1:04 am

      Agree totally with this, in most cases you are using your removable disk to download movies, music or other exe files. Excluding these drives would in my opinion open you up for a wide variety of problems. In more cases than not you are not certain of whom you are getting these from and what they have done to it before you get them.

      All The Best,


    • Chris Hoffman
      February 16, 2013 at 6:19 am

      Sorry, that wasn't phrased clearly -- I think the subtitle was perhaps a bit off.

      You definitely shouldn't exclude removable drives. However, you don't need your antivirus to do a full scan of a removable drive every time it's connected. (This is a feature in some applications, like BitDefender, but it's largely unnecessary.)

      Your antivirus will always scan individual files from the removable drive when you open them.

  4. Rigoberto Garcia
    February 8, 2013 at 9:28 pm

    Thanks Chris, great article. I'm using Microsoft Security Essentials for a couple of years without any problems. highly recommended

  5. Anonymous
    February 8, 2013 at 9:19 pm

    I have tried many Anti-Virus programs, and most of the time I end up getting disappointed during the way. I always end up going back to Microsoft Security Essential.. It's lightweight and it does a great job in my perspective.