Windows Defender
Antivirus in Privacy & security
Free built-in antivirus that runs quietly and catches most malware, though critics report false positives, slowdowns and file uploads to Microsoft.
Free built-in antivirus that runs quietly and catches most malware, though critics report false positives, slowdowns and file uploads to Microsoft.
73 people gave an opinion
- recommend it
- 17
- criticize it
- 56
- approval share
- 23%
Recommended in 9 of 13 months
- November 2025: not recommended
- December 2025: not recommended
- January 2026: recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: recommended
- May 2026: not recommended
- June 2026: recommended
- July 2026: recommended
- August 2026: recommended
- September 2026: recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 17 people recommend itNeeds 10 or more, met.
- 0.3 recommenders for every criticNeeds 2 to 1 or better, not met.
- Recommended in 9 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Good enough, built into Windows
“the built in antivirus and antimalware on Windows is good enough for most users”
Comment from 4 Sep 2026 in “O&O ShutUp10 – The antispy tool for Windows 10 and 11” “Microsoft fixed this with a built in virus scanner on Windows”
Comment from 14 Aug 2026 in “'Not acceptable': Judge orders Google to make rival app store installs easier” “Windows Defender is pretty good now”
Comment from 13 Sep 2026 in “Norton Neo Browser” - Comment from 18 Jul 2026 in “LG monitors silently install software through Windows Update without consent”
Catches malware automatically and quickly
“Defender automatically removes malware (or more correctly, game cracks it thinks are malware) the second it hits my disk”
Comment from 15 Oct 2026 in “Someone on Torrent Sites Kept Fucking with My Sonarr” “Windows Defender definitions are practically real-time”
Comment from 28 Oct 2026 in “Apple's git still trusts the compromised eMudhra certificates” Light and quiet to run
“From my tests defender has minimal impact on performance even when doing a full scan”
Comment from 2 Jan 2026 in “Linux is good now; to feel like you actually own your PC, put Linux on it” “It's very light and silent so I wouldn't go out of my way to turn it off.”
Comment from 11 Jan 2026 in “Replace the Retiring Windows XP with Linux”
What people warn about
Each mark is one comment
Slows disk and CPU use
“a lot of the performance issues are things like crowdstrike and Defender”
Comment from 18 Jun 2026 in “Microsoft new Outlook takes 10 seconds to do what Outlook Classic does instantly” “One of my greats annoyances with Windows is that Microsoft Anti-Virus will lock the file for scanning”
Comment from 12 Nov 2025 in “Terminal Latency on Windows (2024)” “top three CPU usage was and is usually from Antimalware Executable, Microsoft Defender and MS Teams”
Comment from 28 Jan 2026 in “Microsoft forced me to switch to Linux” - Comment from 18 Jun 2026 in “Microsoft new Outlook takes 10 seconds to do what Outlook Classic does instantly”
- Comment from 18 Jun 2026 in “Microsoft new Outlook takes 10 seconds to do what Outlook Classic does instantly”
Uploads suspicious files to Microsoft
“I turned sample submission off permanently via group policy after catching defender uploading places.sqlite out of my Firefox profile.”
Comment from 6 Jun 2026 in “WSL 2 is getting faster Windows file system access” “Microsoft Defender by default could send files to their servers for inspection, and I couldn't see what was sent previously”
Comment from 8 Jun 2026 in “Config Files That Run Code: Supply Chain Security Blindspot” “It has so much telemetry and Microsoft Defender will never-ever give up and will inspect everything , all the time.”
Comment from 14 May 2026 in “Classic 7 is a Windows 10 LTSC mod to look 1:1 to Windows 7” - Comment from 19 Nov 2025 in “Microsoft AI CEO pushes back against critics after recent Windows AI backlash”
- Comment from 8 Nov 2025 in “Apple's "notarisation" – blocking software freedom of developers and users”
False positives on legitimate files
“this generates a ton of false positives”
Comment from 10 Apr 2026 in “CPUid Compromised” “Hello World binary that wasn't compiled by MSVC but by a GNU toolchain was detected as "suspicious" or "potentially unwanted"”
Comment from 11 Apr 2026 in “CPUid Compromised” “Defender automatically removes malware (or more correctly, game cracks it thinks are malware) the second it hits my disk”
Comment from 15 Oct 2026 in “Someone on Torrent Sites Kept Fucking with My Sonarr” - Comment from 10 Apr 2026 in “CPUid Compromised”
Delays new binaries and git work
“Apparently the first time a newly signed binary is run it can take up to 15 minutes for defender to allow it.”
Comment from 8 Dec 2025 in “The Anatomy of a macOS App” “it interfered with git in a way it couldn't detect, so I spent 2 hours diagnosing a bogus FS error”
Comment from 16 Oct 2026 in “Someone on Torrent Sites Kept Fucking with My Sonarr”
What people recommend instead
The same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Windows DefenderThis page | 17 | 56 | 23% | 9 | — | — |
| CrowdStrike Falcon | 6 | 56 | 10% | 4 | — | — |
What people said
40 of the 87 comments that mention it, newest first. Each links to the original comment.
“Windows Defender definitions are practically real-time”
“it interfered with git in a way it couldn't detect, so I spent 2 hours diagnosing a bogus FS error”
“Defender automatically removes malware (or more correctly, game cracks it thinks are malware) the second it hits my disk”
“Windows Defender is pretty good now”
“the built in antivirus and antimalware on Windows is good enough for most users”
“Microsoft fixed this with a built in virus scanner on Windows”
“considered most desktop and start menu shortcuts to be "malware", and removed them silently”
“All of the following products and services are fantastic in 2026”
“Microsoft Defender has solved the anti-virus problem.”
“I tell everyone I know not to get it, and to enable Windows Defender”
“Windows defender has the uncanny ability of spiking up its resource usage at just the wrong time”
“Like a tool that comes with windows that checks that nobody has done that, called windows defender? The tool I have a problem with?”
“a lot of the performance issues are things like crowdstrike and Defender”
“Ive got WPA captures that point to windows defender, even with processes and folders excluded.”
“I am 99% sure it's windows defender doing an absolute crap ton of work on every single file open”
“Microsoft Defender by default could send files to their servers for inspection, and I couldn't see what was sent previously”
“I turned sample submission off permanently via group policy after catching defender uploading places.sqlite out of my Firefox profile.”
“you're not running without Windows Defender enabled except in very very specific circumstances”
“make my MBP run super fucking hot and drain the battery from 100% -> 0% in <2 hours of just basic web browsing.”
“It has so much telemetry and Microsoft Defender will never-ever give up and will inspect everything , all the time.”
“defender updates (not definitions but app update) that won't get applied if you have another anti malware”
“Hello World binary that wasn't compiled by MSVC but by a GNU toolchain was detected as "suspicious" or "potentially unwanted"”
“For may cracks Windows Defender will trip saying "Win32/Keygen" even if there's no actual malware”
“this generates a ton of false positives”
“uses sandboxing or a micro-VM to parse untrusted data”
“Ever since Windows Defender became standard, cleaning up relative's machines has basically turned into disabling some startup apps”
“there is some bound on how much Defender degrades the performance of your machine”
“The time it takes for a site I report there to get blocked is usually measured in hours, not weeks.”
“Someone mentioned Defender, and that could certainly be it, as I have it totally disabled”
“the only notifications I get are from when windows defender blocks something and I need to add an exclusion”
“I found it to be much better after setting an exclusion for the folder that you clone your git repositories to”
“Run MS Defender offline mode”
“top three CPU usage was and is usually from Antimalware Executable, Microsoft Defender and MS Teams”
“disable the various services and drivers that belong to either Windows Defender or the various filesystem filter drivers”
“It's very light and silent so I wouldn't go out of my way to turn it off.”
“From my tests defender has minimal impact on performance even when doing a full scan”
“Apparently the first time a newly signed binary is run it can take up to 15 minutes for defender to allow it.”
“I noticed that Windows Defender will upload "suspicious" files and there's no audit trail of what's being uploaded”
“One of my greats annoyances with Windows is that Microsoft Anti-Virus will lock the file for scanning”
“Microsoft will upload these executables to the cloud by default if you use their antivirus engine”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.