For as cool as it might be to use Microsoft's virtual assistant Cortana, she is also a big reason why the Windows 10 settings are so unfriendly to privacy. Start typing in the "Search Windows" box on the taskbar and Cortana wants to help…or to be turned on. It may be a bummer to lose so many features in Windows 10, but you have to choose if you want as much privacy as possible or if you want as many Windows 10 features as possible. Sorry, but you can't have both.
Be more than an advertising ID for Microsoft; turn these options off unless you really want targeted ads.
Hopefully you customized Windows 10 settings and turned off location. If not, then check out the privacy settings for location and be prepared to scroll. You can turn it off, clear location, control geofencing, and enable and disable specific apps wanting access to your location.
Unless you like to use your webcam a lot, you should consider turning it off. That way you're not part of some secret peep show, just in case some rogue app or a rogue running a RAT (remote access Trojan) hijacks it. One in two Americans were previously clueless about how easy it is to hack a webcam; "experienced hackers can access a webcam in less than a minute and can even turn off the light which shows the webcam is on." You should keep your webcam covered with a sticky note unless you are using it. If you don't want to go back and forth from camera privacy settings, and use your cam for Skype, then at least turn off the other apps.
Just like the webcam, turn your microphone from on-by-default to off. If you need it for Xbox or Skype, then only allow microphone access to those apps.
Settings>Privacy>Speech, inking, & typing
If you use Cortana, then you can't turn this off.
There's no good reason, in my opinion, to automatically let apps access your name, picture, and other account info.
If you really want to hand your contacts to someone else, you can do so here. Otherwise, friends don't let friends just hand out their info.
Cortana may want to access your calendar, but if you killed her off to the best of your ability then do you want other apps accessing your calendar?
Some apps may need to send messages, but you may be using the wrong ones if it also needs permission to "read" your messages.
Unless you are big into syncing and the cloud, you don't need this on. If you turn on USB storage, then Microsoft says it "might impact your privacy" so check with third-party app sites for their privacy policies.
If you use a Microsoft account, instead of a local account, and want all your Windows 10 devices to appear identical, then leave syncing on. If you don't want to send more pieces of yourself to the cloud than happens without your knowledge, then turn it off.
Settings>Privacy>Feedback & diagnostics
You can turn off Windows 10 keylogger by right-clicking on Start and selecting Command Prompt (Admin); enter the following commands one at a time and hit enter after each.
sc delete DiagTrack
sc delete dmwappushservice
echo "" > C:\ProgramData\Microsoft\Diagnosis\ETLLogs\AutoLogger\AutoLogger-Diagtrack-Listener.etl
If you are so inclined, you also can find numerous telemetry and other tweaks for Windows 10 Enterprise.
Settings>Privacy>Background apps is where you can turn on or off the ability of individual apps to receive info even when you are not using them.
Settings>Network & Internet>
Tweak Wi-Fi Sense at Settings>Network & Internet>Wi-Fi then click on "Manage Wi-Fi settings." This is where you turn off Wi-Fi Sense, which could allow your contacts to use your Wi-Fi. There's been a big scandal about Windows 10 sharing your wireless network passwords. Microsoft's Wi-Fi Sense FAQ said it's up to you if you choose to share password-protected Wi-Fi networks with your contacts, and that they won't "see" your password. You can also choose to enter the password manually "on someone's PC instead of sharing access through Wi‑Fi Sense, make sure they can't see what you're typing when you enter it, and then make sure that the Share network with my contacts check box is cleared before you select Connect."
Personally, I believe you should turn it off completely. You can see in the red box that it is possible to share your Wi-Fi with contacts from Outlook, Skype, and even Facebook. Do you really want Microsoft to data-mine your contacts? If you ever sign into a social media site and it tries to suggest people you might know, it happens because one of your online "friends" let that site upload all of his or her contacts. Thanks a whole heap, "friend."
Settings>Network & Internet is also where you can setup a VPN, Proxy, or see your data usage.
Like all of these settings, deciding what to turn off or leave on is a matter of personal preference. You can control what apps and folders show on Start.
Some folks don't want others to know what apps they use most often.
Settings>Update & Security>
Whether you know it or not, your bandwidth is being shared since Microsoft is using it to send "parts of previously downloaded Windows updates and apps" to other PCs on the Internet. Unless you want to be part of Microsoft's P2P network for Windows Updates – and you are by default unless you change the settings – then turn this off. Go to Settings>Update & Security>Windows Update and then select "Advanced options." After that opens, click on "Choose how updates are delivered." If you do nothing, then the settings will be as you see below.
Settings>Update & Security>Windows Defender
If you turn real-time protection off, it's only temporarily; Microsoft will turn it back on automatically. Nevertheless, you might consider turning off "Cloud-based protection" and "Sample submission."
Settings>System>Notifications & actions
If you don't use OneDrive via a Microsoft account, then here is where you can shut off the app's notifications and other notifications. You can also select which icons appear on the taskbar, turning each off or on as well as turning system icons like clock, volume, network, location or action center on or off.
Settings>System>Storage is where you can set up default save locations for documents, music, pictures, videos and apps. Settings>System>Default apps lets you select the apps you want to open your email, music, photos, or to surf the web. Otherwise, your defaults are decided by Microsoft.
BitLocker Drive Encryption
You can clear browsing data in Windows 10 Edge web browser, but there is no native option to automatically clear browsing when you close the browser. Edge settings can be accessed by clicking on the three dots in the upper right corner, then go to privacy and advanced settings.
Hopefully you didn't get whiplash when Microsoft flip-flopped and went from leading the charge to have Do Not Track on by default to shipping Edge with the option turned off. Opt-in by turning Do Not Track "on" and consider changing some of the other settings that were "on" when Edge shipped.
That's likely not all the privacy-wise settings to tweak in Windows 10, but it is all for now.