Much has been made over the past few months about Microsoft’s intent to install Windows 10 on a billion devices. For some, they believe that goal will come at any cost.

So, it wasn’t great news this week – and really didn’t help the company’s trust factor index – when a Windows 10 upgrade started auto-installing on Windows 7 and Windows 8.1 systems. Microsoft has already admitted to delivering small bits of Windows 10 upgrade code to Windows 7 and Windows 8.1 computers, but has also taken great pains to communicate that it will never install the upgrade for anyone that doesn’t want it.

But, this week, as part of a round of Windows updates, the Windows 10 upgrade, though still listed as an optional update, was summarily automatically selected to download the full installation bits and, unless the user was careful, would perform the upgrade uninitiated.

We reached out to Microsoft about the situation, and the company had this to say:

As part of our effort to bring Windows 10 to existing genuine Windows 7 and Windows 8.1 customers, the Windows 10 upgrade may appear as an optional update in the Windows Update (WU) control panel. This is an intuitive and trusted place people go to find Recommended and Optional updates to Windows. In the recent Windows update, this option was checked as default; this was a mistake and we are removing the check.

So, it was an accident. Apparently.

However, one has to wonder – as we get closer to that 1 billion goal – how frantic Microsoft might get and how creative product groups will have to be. During the recent hardware launch in NYC, Terry Myerson revealed that Windows 10 is now running on 110 million devices. And, that’s fantastic. But, the adoption rate is slowing. Rich Hay calculated that for Microsoft to reach its goal of 1 billion devices, Windows 10 needs to be installed on 1.4 million devices daily for 2 years.

Microsoft is making significant inroads to help its cause in co-marketing with hardware vendors, producing and selling its own hardware, upgrading the Xbox One, and other things. But, can it reach 1 billion devices?

Someone suggested to me today that quality drives adoption. However, from my experience Windows 10 is still a work in progress, even from a quality perspective. A goal of 1 billion devices doesn’t seem like a quality goal, but a quantity goal. Get it installed on as many devices as possible and then work out the details.

And, if that’s the case – could we see another accidental auto-upgrade in the future?