Windows 10 has apparenrtly begun to download automatically on computers running Windows 7 and 8.1 without any user permissions.
A discussion on Reddit claims that users of Windows 7 Professional, which already had a payload of nagware for Internet Explorer dumped on it last Patch Tuesday, have seen their machines updating without any user intervention at all.
"This came up on all of our work computers. I told IT. They basically said oh fuck'," said one Redditor.
Another user said they were unable to stop the install because they caught it happening but their son was "not so lucky".
The action also led to comments where life was actually being put at risk by the unilateral action.
"I needed to set up my department's bronchoscopy cart quickly for someone with some sick lungs. I shit you not, when I turned on the computer it had to do a Windows update."
Microsoft had promised to ramp up its efforts to enforce updates last year within Windows Update as it pushes to meet its target of over two billion devices running Windows 10 by 2017.
However, the company has come under increasing scrutiny for the heavy-handed approach to the process, which is having disastrous consequences for some.
"It broke my dad's Bootcamp configuration for OS X. Windows 10 loves to switch to using UEFI and can break other boot loaders."
The problem seems to be affecting all manner of organisations.
"We've been getting calls trickling in all week from doctor's offices, dental practices, B&Bs, and roofing companies - among others - that have been hit by this and it's a fucking mess.
"In some cases the upgrade went OK and the user is just really confused. In others Windows 10 is asking for a login password the user set years ago and hasn't used since, that was fun. In still another it's screwed up access to their shared folders.
"I'm >this< close to telling the techs to disable automatic updates completely for all business customers."
We're currently waiting for confirmation from Microsoft on what's going on here, but it appears to be that users of Windows Professional are now being treated as Personal rather than business users and therefore, being given all the hassle associated with the constant enforcement of updates to Windows 10 that is starting to alienate users so much.
Many users have complained that their computer has been borked by the upgrade and that rolling back hasn't helped.
A lot of users are also questioning whether this sort of thing is actually legal, especially given the litigious nature of the European Union and the words "anti-trust" have been bandied about a number of times.
Others have likened the experience to being violated.
"It happened to me last week. I'm still furious. It feels like someone broke into my house, installed spyware on my computer and rendered my favorite applications useless."
The problem is affecting even system administrators who had previously blocked the upgrade as Microsoft appears to have reclassified it, meaning that it has to be blocked again to avoid this happening.
V3 contacted Microsoft for comment on the claims on Reddit but had received no reply at the time of publication.
Intel wants to get inside your car, despite missing out on mobile
'We'll keep fighting to fight to keep the web free and open,' claim EFF
Breached in March by the same attackers, claim 'insiders'
And all for less than £150, according to Keith