Looks like MS's "Slash & Burn" campaign of installing W10 on unsuspecting W7 & W8.1 user's is starting to bring their numbers up where they need them.
NOTE: My comment is not based on whether W10 is a good/bad OS, just MS's tactics to remove choice for the unsuspecting to fill the MS bottom line.

Clearly, Windows 10 picked up momentum last month. But how?

The simplest explanation: Microsoft’s continued aggressive promotion of Windows 10 through the free upgrade offer to consumer and small business customers running Windows 7 or Windows 8.1 on their personal computers.

Two weeks ago, Microsoft kicked off another surge in Windows 10 installations, which resulted in users reporting that the automatically-downloaded Windows 10 upgrade had been installed without their approval.

More recently, Microsoft again pushed updates at Windows 7 and 8.1 devices that prepare them for an upgrade to Windows 10, a seemingly endless effort that has prompted several developers to come up with upgrade blockers, including GWX Control Panel. Its creator, Josh Mayfield, has updated that blocking tool twice this week to take into account new tactics Microsoft has deployed to force feed the Windows 10 upgrade to customers.