Russia's antitrust authority on Thursday said it had opened an investigation into Microsoft for allegedly abusing its dominance in the antivirus software market.
In a statement, the Federal Anti-monopoly Service said it had taken the decision after being contacted by the Moscow-based internet security giant Kaspersky.
It accuses Microsoft of reducing to six working days the time for third party software vendors to adapt their antivirus packages to the Windows 10 operating system, compared with two months for earlier versions.
When a Windows user installs the latest operating system, its antivirus software is disabled, with Microsoft's Windows Defender system taking over by default.
With only a few days to make the changes necessary to ensure compatibility, software developers like Kaspersky do not have the time to provide users with adequate service.
"As Microsoft itself develops the Windows Defender antivirus system, which automatically becomes active if the third party software products do not have time to be adapted to Windows 10, such measures constitute an unfair advantage for Microsoft," FAS deputy director Anatoli Golomolzine said in the statement.
Kaspersky confirmed approaching the antitrust authority as well as the European Commission in a statement which said the move came "after months of fruitless discussions and multiple exhausting attempts to resolve the issue directly with Microsoft."
In August, the FAS started legal proceedings against US tech giant Apple over the alleged fixing of retail prices for iPhones in Russia.
In the same month, it also hit Google with a $6.75 million fine for abusing its dominant market position by forcing smartphone makers to install its search engine on phones running the Android operating system.