Microsoft says it temporarily disables antivirus software during Windows PC updates to determine the compatibility of software versions.
Microsoft has published a detailed blog post on Windows Defender after Kaspersky filed an antitrust complaint with the EU against it.
Earlier this month, popular antivirus software maker Kaspersky Labs filed an anti-trust complaint with the European Commission. The firm alleged that Microsoft abused its market dominance to push customers towards Windows Defender at the cost of rival antivirus programmes.
"These actions by Microsoft lead to a lower level of protection for users, a limitation on their right to choose, and financial losses both for users and security solution manufacturers," said Kaspersky Labs.
Via a blog post, Microsoft has, without naming Kaspersky, responded to the allegations in detail. While it did explain the objective of Windows Defender and the benefits that come with it, the company also confirmed that it does temporarily disable antivirus software during Windows updates 'to specify which versions of their software are compatible and where to direct customers after updating.'
Microsoft has also patted itself on the back for actively engaging with and supporting a community of over 80 independent software vendors through the Microsoft Virus Initiative (MVI) programme. Through this programme, Microsoft says it ensures that all antivirus software vendors offer “always on” malware protection no matter which software solutions customers use.
Microsoft also said that Windows Defender kicks in if users deactivate or uninstall other antivirus software or if their licenses expire. This way, Microsoft ensures that computers are not left unprotected when no other antivirus software is in operation.
"We’ve worked closely with AV partners to identify changes, provide early builds through the Windows Insider Program and other testing environments, and provide technical guidance through our MVI program," said Microsoft.
"Because AV software can be deeply entwined within the operating system, we doubled down on our efforts to help AV vendors be compatible with the latest updates. By the time the most recent Windows 10 Creators Update released on April 11, for example, nearly all of the antivirus applications that Microsoft tested were fully compatible.
"Only when an AV subscription expires, and the AV application decides to stop providing protection to the customer, will Windows Defender Antivirus begin providing protection," it added.
Microsoft does ask users to uninstall third-party antivirus apps as they may cause the unpopular 'black screen error' that have plagued numerous systems running Windows 10. This option is available to users during the Troubleshooting process but there is no way a user can tell if a third party antivirus app indeed caused his computer's display driver to crash. Kaspersky may have been referring to this Microsoft advisory when it filed the anti-trust complaint with the EC.