Question

How can I turn off/disable personal data sharing to Microsoft in Windows 10?

Overview

Windows 10, by default, has permission to report a huge amount of data back to Microsoft. By clicking through "Express Settings" during installation, you allow Windows 10 to gather up your contacts, calendar details, text and touch input, location data, and a whole lot more. The OS then sends it all back to Microsoft so that it can be used for personalization and targeted ads

Note: You will need admin access to your computer to perform some of these changes. Please consult your local IT support for assistance with this process.

Answer

Before/During Installation

• Do not use Express Settings. Hit Customize, and make sure everything is turned off.
• It's strongly preferred that you use a local account with Windows 10. This is opposed to the ability to create an account tied to a Windows Live ID. As always you should work from a standard account and escalate privileges as needed.

After Installation

• Go to Settings > Privacy, and disable everything, unless there are some things you really need.
• While within the Privacy page, go to Feedback, select Never in the first box, and Basic in the second box.
• Go to Settings > Update and Security > Advanced Options > Choose how updates are delivered, and turn the first switch off.
• Disable Cortana by going to Notebook > Settings and turn off the Cortana settings
• (Optional) Disable web search in Search by going to Settings, and turning off Search online and include web results.

Additional steps

• Open up the Command Prompt by launching cmd as an administrator, and enter the following:

sc delete DiagTrack
sc delete dmwappushservice
echo "" > C:\ProgramData\Microsoft\Diagnosis\ETLLogs\AutoLogger\AutoLogger-Diagtrack-Listener.etl

• Open up the Group Policy Editor by launching gpedit.msc as an administrator. Go through Computer Configuration > Administrative Templates > Windows Components > Data Collection and Preview Builds. 
  • Double click Telemetry, hit Disabled
• While still in the Group Policy Editor, go through Computer Configuration > Administrative Templates > Windows Components > OneDrive
  • Double click Prevent the usage of OneDrive for file storage, hit Enabled, then apply.
• While still in the Group Policy Editor, go through Computer Configuration > Administrative Templates > Windows Components > Windows Defender
  • Double click Turn Off Windows Defender, hit Enabled, then apply.
• Open up the Registry Editor by launching regedit as an administrator.
  • Note: Backup your registry before making any changes to the registry
• Go through HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\DataCollection, select Allow Telemetry, change its value to 0, then apply.

Optional - Privacy Protection

• Replace Microsoft Edge/Internet Explorer with Firefox or Chrome
• Replace Windows Media Player with VLC or MPC-HC
• Replace Groove Music with Foobar2000, Winamp, or MusicBee.
• Replace Photos/Windows Photo Viewer with ImageGlass or IrfanView.