Microsoft would really, really, really like you to upgrade to Windows 10. So much so that even if you've opted not to request the upgrade, you'll get it anyway, even if you never intend to install it.

The software giant confirmed to The Register on Thursday that it's been pushing out the necessary files for the upgrade to Windows 7 and Windows 8.1 systems via Windows Update, even if you haven't bothered to "reserve" an upgrade using Redmond's adware app.

"For those who have chosen to receive automatic updates through Windows Update, we help customers prepare their devices for Windows 10 by downloading the files necessary for future installation," a Microsoft spokesperson told El Reg via email. "This results in a better upgrade experience and ensures the customer’s device has the latest software."

The trouble with this, of course, is that the upgrade to Windows 10 is no common system update. The actual amount that will be downloaded and stored on your system varies. But by way of example, the install media we have for the 64-bit version of Windows 10 clocks in at around 3GB.

Being forced to download that is bound to be a burden, not just on systems with limited disk space, but particularly for people with metered data connections.

Redmond was careful to say that these unwanted bits will only be pushed out to people "who have chosen to receive automatic updates through Windows Update." Yet receiving automatic updates is the default setting, and switching it off, of course, means you'll be endangering your system by not receiving potentially critical security updates.

There is a bright side for those worried about their disk space, though. Microsoft told The Reg that it is possible to remove the Windows 10 update files using the Disk Cleanup utility.

"Those who remove the Windows 10 upgrade files can still upgrade later," the spokesperson helpfully said.

No word on what you should do if your internet bandwidth is at a premium, though.

As far as rationale, The Register was told, "This is an industry practice that reduces time for installation and ensures device readiness." ®