Microsoft defends move to disable rival antivirus, cites compatibility issues

Microsoft has come forward and admitted that it does, at times, disable third-party antivirus programs in Windows 10, following a barrage of complaints from Kaspersky on exactly this matter.

It was last autumn that the security company first began complaining about Microsoft engaging in anti-competitive practices to muscle out third-party antivirus solutions, with Kaspersky specifically noting that when users upgrade Windows 10, ‘incompatible’ antivirus software can be deactivated in favour of Microsoft’s own Windows Defender.

This month, Kaspersky has even gone as far as filing an anti-trust complaint against Microsoft in Europe.

While not addressing this specific issue or Kaspersky directly, as the BBC spotted, Microsoft has made a blog post explaining that in a small percentage of cases, third-party antivirus software can be temporarily disabled in Windows 10.

Microsoft observed that antivirus software is often deeply entwined in the guts of the OS, and if it isn’t made fully compatible with a new update to Windows 10, this can cause issues.

In most cases, antivirus apps are fully compatible – Microsoft notes that 95% of all Windows 10 machines with a third-party antivirus were fine in the compatibility stakes when it came to the last major upgrade (the Creators Update).

But for the small number of apps which weren’t, Microsoft needed to take action, and says it built in a feature to prompt users to install a new (compatible) version of their antivirus post-update.

Microsoft explains: “To do this, we first temporarily disabled some parts of the AV software when the update began. We did this work in partnership with the AV partner to specify which versions of their software are compatible and where to direct customers after updating.”

Deep dispute

So there you have it – a Windows 10 upgrade can potentially lead to an antivirus being disabled, albeit on a ‘temporary’ basis. Which doesn’t sound unreasonable on the face of it, although Kaspersky’s arguments against Microsoft’s practices run pretty deep.

The security firm believes that a central problem is the fact that antivirus vendors aren’t given nearly enough time to ensure compatibility of their software with a fresh upgrade of Windows 10 – and of course those major updates are now coming twice per year.

And Kaspersky has further accused Microsoft of various bits of trickery to try to get people to use Windows Defender rather than another security solution, as we discussed last year.

It’s a messy issue, for sure, and it’ll be interesting to see Kaspersky’s response to Microsoft’s explanation here.