Windows 8.1 - Prevent apps from using your advertising ID
Windows 8.1 will automatically create advertising ID out of your Microsoft account. This advertising ID is used to display advertising across apps downloaded from the Windows Store.
To prevent apps from using your advertising ID, follow the below procedure:
Head to the Charms Bar (Windows key + C) > Settings > Change PC Settings
Go to Privacy > General
Turn off "Lets apps use my advertising ID for experiences accross apps (turning this off will reset your ID)".