Since I don't use OneDrive or any version of MS Office (in fact since I managed to install W10 without a MS account I suspect it's can't as well as don't), am I protected against their attempts to seize my information?
They will still collect what is called "metadata" - things relating to how you use your computer.
I used to explain metadata by saying if they came across was a file called "Next Year's Redundancies", they could draw conclusions even if they could not open the file. Even the size of the file could be useful. In WWII, the British used "traffic analysis" well before the German codes were readable. Knowing who was talking to who gave invaluable insights into strategy. US intelligence services are known still to use this method.
Microsoft know a lot about your computer already. Make, model, hardware fitted, location and even the software being used are readily accessible to them. The aim is to translate that into revenue. Remember how much you paid for this version of Windows? They used to make MILLIONS from those Windows sales, and they want to get that money flowing again, so they are selling YOU to advertisers.
I was going to add that if data on my hard drive was encrypted, would that also prevent MS getting their hands on it? However, in view of Nick's comment on the last sentence of Andrew's that I've quoted:
If the device is switched on and connected to the internet, and is vulnerable to remote access, then encryption is not going to stop people accessing your information because, as you also pointed out, just copying from an encrypted hard drive would decrypt it automatically before it left your machine.
are you saying that MS or other entities could just swipe files off the hard drive anyway and be able to read them even though they were encrypted? If so, what's the point of encryption?
Encryption is a major barrier to those with physical access. Taking the drive out and putting it in another machine would just show gobbledygook.
Those accessing a computer as another user, even an Administrator, would not be able to access a user's files. It is common for an admin to access a computer across a network in order to diagnose and fix faults; they do so under their OWN username, so can not read the main user's documents. Unless you have the user's credentials, their files are locked away.
Should a computer be compromised by malware, or be running screen-sharing software (a common tactic used by scammers), then the user's files are fully accessible.
It is unclear whether the System account, used internally by Windows, can bypass these protections. It is unlikely that Microsoft would actually use it if it could, but you can bet that malware writers will have tried it.
